UBB.threads PHP Forum Software Community Forums Resources and Customizing How Do I? Post Layout Settings Not Working

could be there are some null(empty) values stored for some reason..And there should not be.
goto cp-display=general
expand forum display settings.
Check that Default Topics Per Page has a value.
then do the same for Topic & Post Page Settings
for Default Replies Per Page
also Including Available Display Modes
In fact just type over them again
and hit the update button at the bottom

Then try again.