There was a similar problem when someone was installing Ubercart at this thread: http://www.ubercart.org/forum/support/3337/installation_error_call_undef....

This honestly shouldn't happen since the quote modules are dependent on uc_product to begin with. Drupal should ensure that they're loaded in the correct order.

What were you doing when that error started showing up?

Hey Lyle,

Thanks for the quick reply. I originally had a previous dev version installed from 2008-05-09. I deleted the ubercart folder from my drupal/sites/all/modules folder and downloaded the latest dev version into the same folder. Now when going to the front page of my site, I am getting the error with the white screen of death. I just downloaded the latest dev version again with the same problem.

Cheers,

Jon Antoine
www.antoinesolutions.com

I read the posted link and tried some of the suggestions. Starting off I tried to update Drupal, but I can't update without logging in and I can't login because of the error. I removed the shipping folder from ubercart and was able to access the site, so I logged in and ran the update script. There were no updates, but I told it to update anyways. I then put the shipping folder back into the ubercart folder and get the error again with the white screen of death. I did notice that changes were made to the uc_quote.module file between the two dev versions I was using, but I haven't found that ubercart has an online diff feature to see what was changed.

Cheers,

Jon Antoine
www.antoinesolutions.com

There's got to be something screwy going on in your system table. Look through it and make sure that the filepaths to the modules are all correct and up to date. If there are any that are wrong, change them, and if there are any duplicates, be sure to delete them. I would go ahead and disable all of the Ubercart modules by setting the status column to 0.

If there are in fact duplicate rows in the system table, try to find them in the filesystem and get rid of them. I've found I'd accidentally copied all of Ubercart into a module's folder before. There should be only one copy of any module in a Drupal site.

I think I know whats going on. During the process of deleting the old dev version and checking out a new one, I was trying to write a batch file to do this for me and after deleting the old ubercart folder, I accidentally checked out the ubercart module directly into the drupal/sites/all/modules folder rather into an ubercart sub folder. From what it sounds like is that if I would have visited the site under these conditions they would have created table entries that would have messed up the database. Let me know if this sounds like it could have caused the problem.

Cheers,

Jon Antoine
www.antoinesolutions.com

Sounds possible. I still think the dependency checker should have kept the uc_quote module from being enabled if there wasn't a uc_product module, but I guess it can't be completely fool-proof.