I keep getting crashes:
No mods:
---- Minecraft Crash Report ----
// Don't do that.

Time: 1/12/13 5:05 PM
Description: Unexpected error

java.lang.NullPointerException
at org.lwjgl.opengl.GL11.glGetError(GL11.java:1279)
at net.minecraft.client.Minecraft.d(SourceFile:464)
at net.minecraft.client.Minecraft.J(SourceFile:586)
at net.minecraft.client.Minecraft.run(SourceFile:534)
at java.lang.Thread.run(Unknown Source)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at org.lwjgl.opengl.GL11.glGetError(GL11.java:1279)

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [ays['TheExelot'/1401647, l='MpServer', x=-1276.30, y=25.75, z=1257.70]]
Chunk stats: MultiplayerChunkCache: 441
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (-1351,19,1254), Chunk: (at 9,1,6 in -85,78; contains blocks -1360,0,1248 to -1345,255,1263), Region: (-3,2; contains chunks -96,64 to -65,95, blocks -1536,0,1024 to -1025,255,1535)
Level time: 15113671 game time, 16024464 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Forced entities: 191 total; [qr['Zombie'/1413497, l='MpServer', x=-1311.47, y=63.00, z=1290.05], px['item.item.dyePowder.black'/1411831, l='MpServer', x=-1327.81, y=58.13, z=1221.97], qr['Zombie'/1395008, l='MpServer', x=-1241.44, y=30.00, z=1248.97], qd['Enderman'/1412797, l='MpServer', x=-1221.50, y=36.00, z=1316.63], ph['Squid'/1411813, l='MpServer', x=-1227.41, y=60.34, z=1262.75], qd['Enderman'/1413960, l='MpServer', x=-1301.44, y=44.00, z=1313.47], qp['Spider'/1412234, l='MpServer', x=-1314.91, y=63.00, z=1293.47], qn['Skeleton'/1412231, l='MpServer', x=-1316.63, y=63.17, z=1295.16], qp['Spider'/1412230, l='MpServer', x=-1316.63, y=63.00, z=1295.16], qd['Enderman'/1413959, l='MpServer', x=-1301.50, y=45.00, z=1316.50], px['item.item.egg'/1413953, l='MpServer', x=-1251.13, y=65.63, z=1264.88], ph['Squid'/1411798, l='MpServer', x=-1283.44, y=59.00, z=1322.50], ph['Squid'/1411797, l='MpServer', x=-1284.78, y=59.38, z=1320.22], px['item.item.egg'/1379274, l='MpServer', x=-1251.13, y=65.63, z=1264.13], ph['Squid'/1411800, l='MpServer', x=-1281.31, y=59.34, z=1314.66], qr['Zombie'/1411327, l='MpServer', x=-1225.50, y=34.00, z=1317.50], ph['Squid'/1411783, l='MpServer', x=-1334.03, y=61.34, z=1202.50], qn['Skeleton'/1413441, l='MpServer', x=-1332.50, y=65.00, z=1316.50], qr['Zombie'/1413989, l='MpServer', x=-1204.50, y=88.00, z=1223.50], pc['Ocelot'/1413987, l='MpServer', x=-1250.50, y=80.00, z=1209.50], qc['Creeper'/1412314, l='MpServer', x=-1306.50, y=39.00, z=1308.50], qc['Creeper'/1412316, l='MpServer', x=-1309.50, y=39.00, z=1306.50], px['item.item.dyePowder.black'/1413421, l='MpServer', x=-1330.26, y=59.13, z=1203.26], qn['Skeleton'/1412819, l='MpServer', x=-1267.50, y=79.00, z=1268.50], ph['Squid'/1410633, l='MpServer', x=-1329.31, y=61.30, z=1227.97], qc['Creeper'/1413934, l='MpServer', x=-1349.50, y=26.00, z=1229.50], qc['Creeper'/1413933, l='MpServer', x=-1351.47, y=26.00, z=1225.97], qr['Zombie'/1413376, l='MpServer', x=-1289.09, y=36.00, z=1329.91], pe['Sheep'/1355414, l='MpServer', x=-1223.50, y=64.00, z=1336.50], oz['Cow'/1401653, l='MpServer', x=-1281.53, y=60.00, z=1262.84], oz['Cow'/1401652, l='MpServer', x=-1281.55, y=60.00, z=1264.63], oz['Cow'/1401655, l='MpServer', x=-1279.17, y=60.00, z=1265.32], oz['Cow'/1401654, l='MpServer', x=-1278.10, y=60.00, z=1265.41], oz['Cow'/1401649, l='MpServer', x=-1276.97, y=59.56, z=1258.50], qn['Skeleton'/1412660, l='MpServer', x=-1289.50, y=73.00, z=1191.50], oz['Cow'/1401651, l='MpServer', x=-1278.43, y=60.00, z=1261.64], oz['Cow'/1401650, l='MpServer', x=-1279.64, y=59.36, z=1258.47], qp['Spider'/1405442, l='MpServer', x=-1307.97, y=67.00, z=1230.25], oz['Cow'/1401661, l='MpServer', x=-1279.50, y=64.20, z=1264.19], py['Minecart'/1401660, l='MpServer', x=-1279.50, y=64.50, z=1264.19], qr['Zombie'/1413625, l='MpServer', x=-1232.19, y=80.00, z=1315.60], oz['Cow'/1401663, l='MpServer', x=-1278.06, y=60.00, z=1266.55], oz['Cow'/1401662, l='MpServer', x=-1279.16, y=60.00, z=1266.53], oz['Cow'/1401657, l='MpServer', x=-1275.16, y=64.00, z=1264.53], oz['Cow'/1401656, l='MpServer', x=-1275.47, y=60.00, z=1263.48], oz['Cow'/1401659, l='MpServer', x=-1277.50, y=64.20, z=1263.82], py['Minecart'/1401658, l='MpServer', x=-1277.50, y=64.50, z=1263.82], oz['Cow'/1345194, l='MpServer', x=-1280.70, y=60.00, z=1265.27], oz['Cow'/1345195, l='MpServer', x=-1280.38, y=60.00, z=1259.88], qr['Zombie'/1413607, l='MpServer', x=-1307.00, y=67.00, z=1184.59], oz['Cow'/1345198, l='MpServer', x=-1278.26, y=60.21, z=1258.47], qr['Zombie'/1403824, l='MpServer', x=-1304.69, y=25.00, z=1249.78], py['Minecart'/1345189, l='MpServer', x=-1275.50, y=64.50, z=1263.50], oz['Cow'/1345190, l='MpServer', x=-1275.50, y=64.20, z=1263.50], oz['Cow'/1345179, l='MpServer', x=-1280.13, y=60.00, z=1266.56], qc['Creeper'/1408754, l='MpServer', x=-1271.44, y=67.00, z=1313.94], oz['Cow'/1345178, l='MpServer', x=-1275.78, y=60.00, z=1266.50], oz['Cow'/1345177, l='MpServer', x=-1276.43, y=60.00, z=1264.69], oz['Cow'/1345182, l='MpServer', x=-1279.96, y=60.00, z=1264.29], oz['Cow'/1345180, l='MpServer', x=-1281.53, y=60.00, z=1258.88], oz['Cow'/1345175, l='MpServer', x=-1280.69, y=60.00, z=1261.70], qc['Creeper'/1407660, l='MpServer', x=-1231.53, y=96.00, z=1238.06], ays['TheExelot'/1401647, l='MpServer', x=-1276.30, y=25.75, z=1257.70], qc['Creeper'/1407659, l='MpServer', x=-1234.50, y=95.00, z=1228.50], qn['Skeleton'/1410788, l='MpServer', x=-1248.50, y=96.00, z=1225.50], qn['Skeleton'/1404846, l='MpServer', x=-1350.50, y=65.00, z=1327.50], pe['Sheep'/1401696, l='MpServer', x=-1316.53, y=71.00, z=1205.47], oz['Cow'/1379120, l='MpServer', x=-1278.70, y=60.00, z=1263.57], pe['Sheep'/1401701, l='MpServer', x=-1331.50, y=66.00, z=1307.53], pe['Sheep'/1401702, l='MpServer', x=-1328.53, y=64.00, z=1307.53], qc['Creeper'/1414624, l='MpServer', x=-1291.50, y=54.88, z=1270.50], pc['Ocelot'/1401706, l='MpServer', x=-1215.50, y=96.00, z=1307.50], pe['Sheep'/1401708, l='MpServer', x=-1287.53, y=73.00, z=1181.53], pe['Sheep'/1401709, l='MpServer', x=-1285.47, y=73.00, z=1178.53], qr['Zombie'/1411623, l='MpServer', x=-1271.47, y=37.00, z=1301.00], oz['Cow'/1341644, l='MpServer', x=-1281.53, y=60.00, z=1260.38], px['item.item.egg'/1376700, l='MpServer', x=-1251.88, y=65.63, z=1264.88], qr['Zombie'/1407198, l='MpServer', x=-1358.44, y=42.00, z=1262.00], oz['Cow'/1376701, l='MpServer', x=-1276.06, y=60.00, z=1261.91], oz['Cow'/1341642, l='MpServer', x=-1281.53, y=60.00, z=1264.21], qn['Skeleton'/1414608, l='MpServer', x=-1336.50, y=84.00, z=1181.50], qr['Zombie'/1412700, l='MpServer', x=-1320.50, y=50.00, z=1249.50], qr['Zombie'/1412699, l='MpServer', x=-1322.50, y=50.00, z=1249.50], pe['Sheep'/1401695, l='MpServer', x=-1319.47, y=63.00, z=1206.53], qr['Zombie'/1412698, l='MpServer', x=-1321.50, y=50.00, z=1249.50], pe['Sheep'/1401694, l='MpServer', x=-1327.47, y=64.00, z=1307.53], pe['Sheep'/1401693, l='MpServer', x=-1327.47, y=64.00, z=1307.53], oz['Cow'/1401666, l='MpServer', x=-1281.55, y=60.00, z=1266.99], py['Minecart'/1401667, l='MpServer', x=-1281.50, y=64.50, z=1264.50], oz['Cow'/1401664, l='MpServer', x=-1280.42, y=60.00, z=1263.06], oz['Cow'/1401665, l='MpServer', x=-1275.47, y=60.00, z=1265.84], oz['Cow'/1401668, l='MpServer', x=-1281.50, y=64.00, z=1263.47], qc['Creeper'/1401669, l='MpServer', x=-1309.44, y=28.00, z=1258.03], qp['Spider'/1401672, l='MpServer', x=-1303.19, y=26.08, z=1249.16], px['item.item.egg'/1376330, l='MpServer', x=-1251.88, y=65.63, z=1264.13], qn['Skeleton'/1408857, l='MpServer', x=-1349.50, y=70.00, z=1239.50], px['item.item.egg'/1393393, l='MpServer', x=-1251.88, y=65.63, z=1264.13], qc['Creeper'/1414150, l='MpServer', x=-1349.50, y=25.00, z=1221.50], qn['Skeleton'/1412520, l='MpServer', x=-1239.50, y=81.00, z=1262.50], qn['Skeleton'/1412518, l='MpServer', x=-1292.50, y=19.00, z=1329.96], qn['Skeleton'/1412517, l='MpServer', x=-1297.56, y=16.00, z=1329.50], oy['Chicken'/1354626, l='MpServer', x=-1251.84, y=67.47, z=1264.16], oy['Chicken'/1354627, l='MpServer', x=-1251.16, y=67.36, z=1264.16], oy['Chicken'/1354624, l='MpServer', x=-1251.16, y=67.11, z=1264.84], oy['Chicken'/1354625, l='MpServer', x=-1251.84, y=67.40, z=1264.84], oy['Chicken'/1354630, l='MpServer', x=-1251.84, y=67.03, z=1264.84], oy['Chicken'/1354631, l='MpServer', x=-1251.16, y=67.31, z=1264.84], oy['Chicken'/1354628, l='MpServer', x=-1251.84, y=67.25, z=1264.16], oy['Chicken'/1354629, l='MpServer', x=-1251.84, y=67.55, z=1264.84], oy['Chicken'/1354632, l='MpServer', x=-1251.16, y=67.45, z=1264.84], qc['Creeper'/1413096, l='MpServer', x=-1255.50, y=76.00, z=1294.50], qp['Spider'/1407339, l='MpServer', x=-1228.50, y=96.00, z=1233.50], qc['Creeper'/1412023, l='MpServer', x=-1313.50, y=17.00, z=1312.50], qr['Zombie'/1412586, l='MpServer', x=-1322.50, y=18.00, z=1242.50], qr['Zombie'/1412585, l='MpServer', x=-1322.50, y=18.00, z=1239.50], qn['Skeleton'/1414221, l='MpServer', x=-1286.50, y=44.00, z=1235.50], qn['Skeleton'/1414220, l='MpServer', x=-1341.50, y=67.00, z=1308.50], qn['Skeleton'/1409803, l='MpServer', x=-1208.50, y=38.00, z=1326.50], pc['Ocelot'/1413081, l='MpServer', x=-1201.50, y=89.00, z=1221.50], pc['Ocelot'/1413082, l='MpServer', x=-1201.50, y=89.00, z=1221.50], pc['Ocelot'/1413083, l='MpServer', x=-1201.50, y=89.00, z=1221.50], qc['Creeper'/1402521, l='MpServer', x=-1304.25, y=20.00, z=1254.00], qc['Creeper'/1402522, l='MpServer', x=-1300.00, y=19.00, z=1261.44], qr['Zombie'/1412356, l='MpServer', x=-1274.50, y=70.00, z=1200.03], qp['Spider'/1412363, l='MpServer', x=-1351.50, y=68.00, z=1295.50], qn['Skeleton'/1414273, l='MpServer', x=-1300.50, y=64.00, z=1299.50], qc['Creeper'/1413339, l='MpServer', x=-1303.50, y=64.00, z=1292.50], qc['Creeper'/1413337, l='MpServer', x=-1309.50, y=64.00, z=1286.50], oy['Chicken'/1354620, l='MpServer', x=-1251.16, y=67.52, z=1264.16], oy['Chicken'/1354621, l='MpServer', x=-1251.84, y=67.31, z=1264.84], oy['Chicken'/1354622, l='MpServer', x=-1251.84, y=67.61, z=1264.16], oy['Chicken'/1354623, l='MpServer', x=-1251.84, y=67.56, z=1264.84], oy['Chicken'/1354616, l='MpServer', x=-1251.84, y=67.36, z=1264.84], oy['Chicken'/1354617, l='MpServer', x=-1251.16, y=67.50, z=1264.84], oy['Chicken'/1354618, l='MpServer', x=-1251.84, y=67.26, z=1264.16], oy['Chicken'/1354619, l='MpServer', x=-1251.84, y=67.19, z=1264.84], oy['Chicken'/1354612, l='MpServer', x=-1251.84, y=67.12, z=1264.84], oy['Chicken'/1354613, l='MpServer', x=-1251.16, y=67.31, z=1264.16], oy['Chicken'/1354614, l='MpServer', x=-1251.16, y=67.55, z=1264.84], oy['Chicken'/1354615, l='MpServer', x=-1251.84, y=67.25, z=1264.16], qr['Zombie'/1411328, l='MpServer', x=-1224.50, y=34.00, z=1317.50], oy['Chicken'/1354608, l='MpServer', x=-1251.16, y=67.48, z=1264.16], oy['Chicken'/1354609, l='MpServer', x=-1251.16, y=67.35, z=1264.84], oy['Chicken'/1354610, l='MpServer', x=-1251.16, y=67.36, z=1264.84], oy['Chicken'/1354611, l='MpServer', x=-1251.84, y=67.38, z=1264.16], oy['Chicken'/1354605, l='MpServer', x=-1251.84, y=67.54, z=1264.84], px['item.item.egg'/1375901, l='MpServer', x=-1251.13, y=65.63, z=1264.88], oy['Chicken'/1354604, l='MpServer', x=-1251.84, y=67.33, z=1264.84], oy['Chicken'/1354607, l='MpServer', x=-1251.16, y=67.31, z=1264.84], oy['Chicken'/1354606, l='MpServer', x=-1251.16, y=67.38, z=1264.84], oy['Chicken'/1354601, l='MpServer', x=-1251.16, y=67.09, z=1264.16], oy['Chicken'/1354600, l='MpServer', x=-1251.84, y=67.24, z=1264.84], oy['Chicken'/1354603, l='MpServer', x=-1251.84, y=67.36, z=1264.16], oy['Chicken'/1354602, l='MpServer', x=-1251.16, y=67.42, z=1264.84], oy['Chicken'/1354597, l='MpServer', x=-1251.16, y=67.64, z=1264.84], oy['Chicken'/1354596, l='MpServer', x=-1251.16, y=67.26, z=1264.84], oy['Chicken'/1354599, l='MpServer', x=-1251.84, y=67.61, z=1264.16], oy['Chicken'/1354598, l='MpServer', x=-1251.84, y=67.52, z=1264.84], oy['Chicken'/1354593, l='MpServer', x=-1251.16, y=67.28, z=1264.84], oy['Chicken'/1354592, l='MpServer', x=-1251.84, y=67.42, z=1264.84], oy['Chicken'/1354595, l='MpServer', x=-1251.16, y=67.54, z=1264.84], qp['Spider'/1413788, l='MpServer', x=-1297.81, y=67.00, z=1235.78], oy['Chicken'/1354594, l='MpServer', x=-1251.84, y=67.47, z=1264.84], ow['Bat'/1401878, l='MpServer', x=-1279.25, y=52.10, z=1260.41], qc['Creeper'/1413792, l='MpServer', x=-1305.44, y=67.00, z=1227.02], oy['Chicken'/1354590, l='MpServer', x=-1251.16, y=67.53, z=1264.84], oy['Chicken'/1354591, l='MpServer', x=-1251.84, y=67.40, z=1264.16], oy['Chicken'/1354588, l='MpServer', x=-1251.16, y=67.43, z=1264.16], oy['Chicken'/1354589, l='MpServer', x=-1251.84, y=67.61, z=1264.16], oy['Chicken'/1354586, l='MpServer', x=-1251.16, y=67.52, z=1264.84], oy['Chicken'/1354587, l='MpServer', x=-1251.16, y=67.58, z=1264.84], oy['Chicken'/1354584, l='MpServer', x=-1251.84, y=67.52, z=1264.84], oy['Chicken'/1354585, l='MpServer', x=-1251.84, y=67.33, z=1264.84], oy['Chicken'/1354582, l='MpServer', x=-1251.16, y=67.53, z=1264.16], oy['Chicken'/1354583, l='MpServer', x=-1251.16, y=67.50, z=1264.16], oy['Chicken'/1354580, l='MpServer', x=-1251.16, y=67.53, z=1264.16], oy['Chicken'/1354581, l='MpServer', x=-1251.84, y=67.36, z=1264.84], oy['Chicken'/1354578, l='MpServer', x=-1251.16, y=67.52, z=1264.16], oy['Chicken'/1354579, l='MpServer', x=-1251.84, y=67.41, z=1264.84], oy['Chicken'/1354576, l='MpServer', x=-1251.16, y=67.39, z=1264.84], oy['Chicken'/1354577, l='MpServer', x=-1251.84, y=67.55, z=1264.84], oy['Chicken'/1354575, l='MpServer', x=-1251.16, y=67.43, z=1264.16], oy['Chicken'/1354574, l='MpServer', x=-1251.84, y=67.54, z=1264.16], oy['Chicken'/1354573, l='MpServer', x=-1251.16, y=67.41, z=1264.84], oy['Chicken'/1354572, l='MpServer', x=-1251.84, y=67.52, z=1264.84], oy['Chicken'/1354571, l='MpServer', x=-1251.84, y=67.46, z=1264.84], pd['Pig'/1354570, l='MpServer', x=-1263.59, y=62.00, z=1252.59], pd['Pig'/1354569, l='MpServer', x=-1263.53, y=62.00, z=1255.81], pd['Pig'/1354568, l='MpServer', x=-1259.50, y=62.00, z=1252.79], pd['Pig'/1354567, l='MpServer', x=-1266.19, y=62.00, z=1257.97], qo['Slime'/1405805, l='MpServer', x=-1275.69, y=36.00, z=1287.31]]
Retry entities: 0 total; []
Stacktrace:
at ayp.a(SourceFile:281)
at net.minecraft.client.Minecraft.b(SourceFile:1871)
at net.minecraft.client.Minecraft.run(SourceFile:548)
at java.lang.Thread.run(Unknown Source)

– System Details –
Details:
Minecraft Version: 1.4.7
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_10, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 288550816 bytes (275 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 2486 (139216 bytes; 0 MB) allocated, 2395 (134120 bytes; 0 MB) used
Suspicious classes: No suspicious classes found.
IntCache: cache: 0, tcache: 0, allocated: 3, tallocated: 63
LWJGL: 2.4.2
OpenGL: ~_ERROR~ NullPointerException: null
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Texture Pack: Default
Profiler Position: N/A (disabled)
Vec3 Pool Size: 1046 (58576 bytes; 0 MB) allocated, 830 (46480 bytes; 0 MB) used