Upgrade error

After I select Upgrade I get the following:
Fatal error: Call to a member function getBitVersion() on a non-object in /home/content/a/x/c/..../html/bitweaver/temp/templates_c/basic/en/%%8D8DCA19F9%%install.tpl.php on line 10

Any ideas how to fix this?
I'm trying to upgrade from tikiwiki, but not even getting to that point.

I also tried upgrade of Tiki using bitweaver version 2.5. I definitely get further in the process, but then get the following error right before the actual conversion. I must be missing a step for these two conversions.

Fatal error: Call to undefined method BitSystem::registerUpgrade() in /home/content/a/x/c/..<mysite_info>../html/wiki/kernel/admin/upgrade_inc.php on line 472

This is a godaddy hosted site.</mysite_info>

debugging this upgrade stuff is not easy, there are a lot of parts. if you can share more information and know how to use IRC we can probably help you out better if you join the IRC channel and talk with us there. ConnectingToIrc

Also try deleting that cached file. It may just be that the cache file has legacy deprecated code and when it is regenerated it will be cleaned up.