warning: mysqli_real_escape_string() expects parameter 2 to be string, array given in /home/www1/openpublish/includes/database.m

The hook_user "validate" operation is called every time the user account is about to be modified. Without it Profile Checkboxes would fail to perform for all the other applications that have already successfully deployed it.

It's been awhile, but I believe the "validate" operation was used because "submit" was firing too late to properly convert the multiple selections to a single comma-delimited value before saving. So in this case the "validate" operation is being used more like the "presave" operation of hook_nodeapi.

In any event, I will need more information in order to further diagnose this problem.

validate is fired on new accounts, but for whatever reason on edit it isnt fired

This is obviously not normal. I suspect there's a naughty module that's preventing other hook_user 'validate' operations from firing. You'll need to temporary disable any other profile related modules one by one until you find the culprit.

Did you make any progress on this issue? Can we conclude that the above error is not being caused by Profile Checkboxes?

I'm going to close this issue for now, but please reopen if you have new information to share.

Thanks,
John