XF 1.5 Kind of urgently some help needed - Rebuild Thread Information doesn't work

OK, I'm having some kind of problem here.
I am in the process of migrating a forum to xenforo and part of my migration process is rebuilding the thread information with the option 'Rebuild position and post counters' turned on.
And while this always worked fine during my test migrations, it seems to be having quite a few problems now during the live migration.
It just keeps kind of failing without any error message. Usually it doesn't even start the process, just keeps showing the window with


before silently returning to the CP.
Once it started the process and then failed at around thread 1700.
Then after several attempts where it only went as far as


I got it to run again, it started from 0 again. It ran until around 2700 and the finished with the message 'Cache rebuilt successfully' or so. But it wasn't done. The forum has around 6500 threads and it also obviously didn't work, since most of the threads are still not displayed correctly.

Now xenforo finally notified me about some out of memory error 20 minutes ago. I guess that has to do with that issue, even though it only has one such error message and not multiple for multiple failed attempts.
And it just keeps failing and failing. Why is that happening and how can I fix it?

Chris D

XenForo developer
Staff member
What is the exact out of memory error, including the stack trace? It may or may not be related but the full details will help ascertain that and the solution going forward.

Rebuilding the position counters is an extensive operation so it could be hitting memory limits or there could be something else, such as maximum execution time. Have you tried setting the items per page lower than the default 250?