When a blocked users attempts to edit a page in the classic editor they see a large, red-bordered notice that tells them:
*They are unable to edit, but they can still read
*Who blocked them
*Why they are blocked (shows them the block log extract)
*When the block expires
*That they can usually edit their talk page and email other editors and aministrators
*What to do if the block is unclear or doesn't seem relevant
*How to appeal a block (links to policy and guide)
*That they can view and copy the source of a page

In contrast when a blocked user attempts to edit a page in VE
*No notice appears, and editing works as normal
*When they click "Save page" they can review their changes and enter an edit summary as normal

When they try to save their edits they see a small white box with a message that tells them:
*There was a server problem
*Their request was unsuccessful because they have been blocked
They can then choose only "OK" which takes them back to the save page dialog.

This is very bad because
*The message they see appears to say they caused a server error - cue panic mode for non-technical users ("Help! I've broken Wikipedia!" - that is exactly the reaction I would expect from my mother.)
*They have wasted potentially lots of time on an edit they cannot save
*It doesn't tell them what being blocked means
*It doesn't tell them who blocked them or for what reason 
*It doesn't tell them what they can do to get help - they can't ask questions at the page that seems to be about asking questions for example (see Bug 51875)
*It doesn't tell them when the block expires, how they can appeal it or how they can contact anybody.

For some users it is even worse that that - saving fails silently: Bug 51999

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**Version**: unspecified
**Severity**: normal
**See Also**:
https://bugzilla.wikimedia.org/show_bug.cgi?id=51999
https://bugzilla.wikimedia.org/show_bug.cgi?id=51454
https://bugzilla.wikimedia.org/show_bug.cgi?id=51547
https://bugzilla.wikimedia.org/show_bug.cgi?id=53009