Hi, We have just upgraded to 4.2 and the upgrade instructions refer to

9.Click the button that is displayed in the control panel and wait for the upgrade process to complete. This process can take up to 10 minutes depending on the content of your forums. The Control Panel Dashboard will be displayed once the upgrade process is complete. -

When I go to the control panel I don't see any 'button' At the bottom of the page it shows 'Active Forums 4.2.7.0'
If I go to the froums page none of the forums are visable.

I did not get any errors in the upgrade (when installing the module)

Any ideas?
Thanks,

If I go to the froums page none of the forums are visable.

Sounds an awful lot like the problem that I had upgrading to 4.2 from 4.1.  I submitted a support ticket last Friday and got a response today.  They sent me an SQL script to "complete the upgrade".  I'll be testing it tonight when I get home.  I would suggest submitting your own support ticket to make sure you get the proper support.