Registration Bug, Unsure of The Fix

[boxingscene]

I've experienced this issue, on and off, for years.

I would estimate it happens to a handful of users out of every 30 registrations.

When users attempt to register they get the following error during the final step.

Fatal error: Existing data passed is not an array
Called set_existing in [path]/register.php on line 421
in [path]/includes/class_dm.php on line 235

From what I can tell, the user gets added to the database, but he never receives the email to confirm his email and we never get the email to advise of their registration.

I'm on Vbulletin 3.8x.

From what I found, this issue was even happening on VB 4.X. It appears to affect sites that use a slave/master combo.

VB staff solved this bug, in the following thread, but for 4.X.

http://tracker.vbulletin.com/browse/VBIV-10812

It's an issue when the functions.php does a call to the slave and that error comes (if I understand it right) because the info for the new user is not there yet on the slave.

Unsure of how to apply the fix to 3.X.