Changing pages while not logged in sometimes causes Internal Server Error

[Jere Metsäranta]

I am encountering an issue where certain pages of the bug listing can't be opened from the "previous" and "next" buttons of the UI. Instead of opening, they cause an error. This only happens when I am not logged in, it works when I am logged in my account. I encountered this with the Ubuntu bug listing.

Reproduce:

1. Open https://bugs.launchpad.net/ubuntu

2. Sort by descending Number. Direct URL: https://bugs.launchpad.net/ubuntu/+bugs?orderby=-id&start=0

3. Go through pages until you are at the page that starts at the 525th item. Direct URL: https://bugs.launchpad.net/ubuntu/+bugs?orderby=-id&memo=525&start=525

4. Press "Next"-button, it should generate popup error.

Error message with the descending number and next button:

Server error, please contact an administrator. OOPS ID:OOPS-820a570fac1ac0770e019622f6697df2

It also happens if you sort while sorting by ascending number. Press "next" button to reporoduce at this page:

https://bugs.launchpad.net/ubuntu/+bugs?orderby=id&start=101700

Error message with the ascending number and next button:

Server error, please contact an administrator. OOPS ID:OOPS-5ff1f4719525a57b9b978e99946c27ce

It also happens when you sort by ascending number and press "Previous" on this page:

https://bugs.launchpad.net/ubuntu/+bugs?orderby=id&memo=133350&start=133275&direction=backwards

Error message with ascending number and previous button:

Server error, please contact an administrator. OOPS ID:OOPS-97b6fb11d0f14414a6e50df56415dd37