I'm getting these all the time too.

@mmodell is currently importing Gerrit repositories into differential I believe.

fwiw, there are problems with the import T133830: Unmerged changes in Gerrit should not autoclose Phabricator tasks

I received the same error about 5 minutes ago when trying to login to Phabricator via MediaWiki. I closed the tab and clicked on the MediaWiki login button again and it worked.

In T133826#2246628, @Peachey88 wrote:

@mmodell is currently importing Gerrit repositories into differential I believe.

He actually included a change that allows us to import all refs. We can now view all open gerrit changes. Currently he is importing them and there are so many to process.

The problem will subside when the import is finished.

I've reduced the number of phabricator task queue workers, this should eliminate the db errors at the expense of increasing the time to complete the import.

Still happening from time to time today.