Show the right error message to the user

[sharunkumar]

Sometimes a random error occurs and the user has no way to find out what went wrong unless they dig into the console / network logs:

Error in browser console:

Seems like in this case, its an invalid post title

I can work on a PR for this

[aeharding]

No prob!

[Brendan-D15]

I've also seen this error caused by instances blocking commenting/posts from accounts that are actively using a VPN. Switching the VPN off allows them to post/comment again.