Upgrade problem 3.6.4 from 3.5.4

[deep_blue]

hi

i just upgraded my forum from 3.5.4 to 3.6.5. Now when somebody is trying to post anything, page becomes blank. and nothing comes up

second problem is the link to "Go to last post" is showing no thread found

[Marco van Herwaarden]

Did you run Update Thread & Forum Counters as instructed during the upgrade?

To further troubleshoot this, please create a new Style with no Parent set. Now browse the forum using this new style.