Note to RedstoneHelper: Please read this bug and UNDERSTAND IT ! I know my english is not perfect, but please try to understand the problem, and stop to close every bug for "duplicate" reason... All others moderators understand the difference between a size limit problem and a random message error problem, all users understand it, with you and only you don't understand this and close every bug ? I remember when you close my bug report about a centered texture problem, and you close it because of a duplicate with a texture not same on the shields and on the banners... The only solution was to contact jeb to solve the problem, because you don't understand why means "duplicate"... It's not because the target component is the same that the bug is the same!
So now I know the future: you will close this bug (like all others bugs), you will ban me, and I will send another email to jeb because you refuse to understand this bug and because I can't report it :-/ I don't understand why mojang don't ban you, all others moderators are more efficient than you, and why your decision should be more important than all others moderators ?
Else, if this time you read this bug report, maybe you will understand that it's not the same bug, you will understand than hundreds users support this bugs (look at the vote and all other closed bugs votes and comments), and you will reopen the bug MC-97531(for remember other moderator validated it), and close this one.

Note to moderators: This bug report is NOT a duplicate from MC-30955. Mojang don't want correct the tellraw lenght limit: ok no problem, but this bug report is about random error message with book ! It's not "work as intented" that book generate the error "invalid json" when json is valid. If Mojang want limit the command size, it should display an error message like "command lenght is too long", or better: forbid the creation of corrupted book, or may be remove this nonsense limitation for book (I don't speak about tellraw here). A proof that "Work as intented" about the tellraw bug is not related to the book bug is this other bug: MC-70317. The tellraw command is a chat command, with chat limitation: ok. The book is not chat related, that's why the suggest_command don't work (MC-70317), and that's why the limitation for book (and random error message and corrupted book) are not Work As Intented. It should be Mojang to decide if it's intented or not and what is the solution because it's not the same bug. Thanks for your attention.

There are an error in the book with the run_command tag when text command is more than 100 chars length:

1/ If the text in run_command is too long, it is troncated:

Exemple with this book:

/give @p written_book 1 0 {pages:["{\"text\":\"Hello World\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/say Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft\"} }"],title:"",author:""}

The give command is valid, but when I click in the book, the text is truncated
(see screenshot 1)
The command outside the book work with no problem:

/say Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft

2/ If I use a formatted text, there are an error. I try with the same example as 1/, but with yellow color displayed with a tellraw command:

/give @p written_book 1 0 {pages:["{\"text\":\"Hello World\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/tellraw @a {\\\"text\\\":\\\"Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft\\\",\\\"color\\\":\\\"yellow\\\"}\"} }"],title:"",author:""}

When I click on the link, the following error occured:

Invalid json: Unterminated string at line 1 column 89

(see screenshot 2)

The command outside the book work with no problem:

/tellraw @a {"text":"Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft Minecraft","color":"yellow"}

(see screenshot 3)

3/ The real problem with this bug is for tools book, it's impossible to make a custom tools book with complex command. For exemple, this book can spawn a zombie with a Full P4 diamond armor:

/give @p written_book 1 0 {pages:["{\"text\":\"Super Zombie\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/summon Zombie ~ ~1 ~ {ArmorItems:[{tag:{ench:[{id:0,lvl:4}]},id:\\\"minecraft:diamond_boots\\\"},{tag:{ench:[{id:0,lvl:4}]},id:\\\"minecraft:diamond_leggings\\\"},{tag:{ench:[{id:0,lvl:4}]},id:\\\"minecraft:diamond_chestplate\\\"},{id:\\\"minecraft:diamond_helmet\\\",tag:{ench:[{id:0,lvl:4}]} }]}\"} }"],title:"",author:""}

When I click on the link, the following error occured:

Data tag parsing failed: Unbalanced brackets: {ArmorItems:.....{tag:{en

(see screenshot 4)

The command outside the book work with no problem:

/summon Zombie ~ ~1 ~ {ArmorItems:[{tag:{ench:[{id:0,lvl:4}]},id:"minecraft:diamond_boots"},{tag:{ench:[{id:0,lvl:4}]},id:"minecraft:diamond_leggings"},{tag:{ench:[{id:0,lvl:4}]},id:"minecraft:diamond_chestplate"},{id:"minecraft:diamond_helmet",tag:{ench:[{id:0,lvl:4}]} }]}

(see screenshot 5)

The displayed error is always different, for a unique bug.
I report this bug because many users of my book generator report to me this problem, but I can't help them, it's a bug with Minecraft.