Unable to open unfirm jobs

I just wanted to share an experience in hopes it may help someone in the future. We recently ran into an issue where we could not open unfirm jobs (object not set to an instance of an object). It came on suddenly. In time phase, we could see the unfirm jobs, but they did not show in Job Manager. Even more perplexing, was the BAQs would not even return the JobHeads - though we could see them in SQL.

After some intense troubleshooting and step debugging, we ruled out customizations and also traced the issue down to JobEntry.JobMtlBackFlushSens(). Ultimately, this wasnt helpful.

Eventually we discovered the problem was simply UD fields. We all know we have to regen\recycle after UD changes, but what was overlooked was that we have a dedicated appserver for the TaskAgent - this failed to get recycled which caused the issues with the records.

You have to recycle all your AppServers after a Regen.

What Haso said is true, the problem here was there was a mostly unknown appserver that was strictly handling Task Agent, so it got overlooked. The point of my post is be a friendly reminder if anyone ever gets this particular error with MRP.