Was exploring in an old world updated to the 18w08b snapshot. When going to certain locations my game crashes and leaves me with the attached crash report.

Time: 24.02.18 21:50
Description: Exception ticking world

i: Non [a-z0-9/._-] character in path of location: minecraft:CaveSpider
at nx.<init>(SourceFile:36)
at nx.<init>(SourceFile:41)
at atj.g(SourceFile:42)
at atj.b(SourceFile:185)
at bfe.a(SourceFile:86)
at bfe.ac_(SourceFile:104)
at jp.<init>(SourceFile:53)
at sd.b(SourceFile:105)
at se.c(SourceFile:161)
at rx.k_(SourceFile:219)
at net.minecraft.server.MinecraftServer.w(SourceFile:694)
at net.minecraft.server.MinecraftServer.v(SourceFile:627)
at cxd.v(SourceFile:155)
at net.minecraft.server.MinecraftServer.run(SourceFile:532)
at java.lang.Thread.run(Unknown Source)