Failed Ajax request or invalid JSON error with quickSubmit plugin Add Contributor

Software Support
,
24

So here is my weird twist:

Attempting to add a Contributor in the QuickSubmit Form after enabling email optional in AuthorRequirements Plugin settings caused a “Failed Ajax request or invalid JSON error” (OJS V3.3.0.8 ).

I had not upgraded the plugin.

Having nothing left to loose, I upgraded the plugin, and now the Add Contributor seems to work again.