Hi there! I'm pretty new to xoops, but I recognise an error when I see it. This is what I did:
I installed XOOPS 2.2.3a FINAL on my server, then download the Community Pack from this web page and installed some modules. Everything was going ok until I decided to Un-install some of the modules and installing them again. I though this would have no change on my site but it did:
The Main Menu is BLANK, only the title will show. The next errors came in:


Notice [PHP]: Object of class XoopsUser could not be converted to int in file class/theme.php line 442
Notice [PHP]: Only variable references should be returned by reference in file kernel/blockinstance.php line 111
Warning [Xoops]: Smarty error: unable to read resource: "db:system_block_mainmenu.html" in file class/smarty/Smarty.class.php line 1084
Warning [Xoops]: Smarty error: unable to read resource: "db:system_block_mainmenu.html" in file class/smarty/Smarty.class.php line 1084

I need some help because I've just installed XOOPS so I dont mind reinstalling it, but I'm worried that this happens again.
Thanks in advance.

I had similar problems.
I've changed server and now everything is OK. Earlier I was using OmniSecure 3.0 Web Server. It doesn't define HTTP_HOST and I think that was a problem.

Try clearing your template_c directory (except for the index.html file). If you have access, I usually use ftp, then go into your template_c directory and delete everything but the index.html file. I think you can do this another way too. By going to administration/system/preferences/general settings and scroll down to the bottom and just click GO.

Then go to your administration/modules and to the right of system click on the update module icon.

Quest