OK – now the caching issue is out of the way I can see the errors in the console.
Out of interest – I can also see that the forum has topics and posts – so what has changed to make it stop working? Newly added WordPress plugins? Updates to WP plugins? New WP Theme? Something must have changed…
On the front page I am seeing 4 errors listed. The first is making a call to get something from ‘tag.contextweb.com’. This failing as the client is blocking it. I have no idea what it is or why it is beign blocked.
The next is in the tooltips script library. We will come back to that in a minute. The third is from BuddyPress to do with the cookies library and the last is caused by the first two closing down further jQuery scripts.
So lets deal with the tooltips. You have probably started using something new that is either loading its own tooltips library or initialising the Wp loaded one which is conflicting with the SP initialisation. Go to the forum admin > themes > theme editor and load the spFunctions.php file. At the top you can turn the SP tooltips off – change the word true to false – save it – and try the forum again.