Database cleanup between tests is not sufficient enough, eg viewpoints persist.

[Vassyli]

This seems like a weird bug for me, but I am not able to run two independent test files in module/new-day without data infererring with each other, while in the core it seems to work without any issue at all...?

[Vassyli]

Update: The error is due to insufficient database cleanup after every test. We need to look into this and provide a base test that does everything.