Example of JSON text using tellraw command (from Minecraft Wiki):
/tellraw @a ["Hello there, ",

,"."]
Result: Invalid json: malformed JSON at line 1 column 20

Example 2 of JSON text using tellraw command (also from Minecraft Wiki):
/tellraw @a [[[["The "],[["quick ","brown "],[

," jumps "],"over "],"the "],["lazy ","dog."]]]
Result: Invalid json: malformed JSON at line 1 column 37

This bug also exists for the title command, which also uses JSON text.

Both examples were tested in 1.8.8, and they both worked without a problem.