Component in rollback state; assembly is inaccessible now.

I have started using a technique that a guy here showed me. It isn't automatic, but not bad.
Create the assy that has the parts mated as you wish. Then in that assy, intelligently mirror the desired parts, deciding what needs to be mirror parts, and which are instances, and fix them. Now add a new config (other, mirrored, etc). In the main config, suppress the mirrored parts, and in the other config suppress the original parts.
The advantage of this method is that it's fairly quick and usually the assy with the mirrored parts fixed in it can then be used in the parent assy as is by changing the config - the mates probably still apply properly, or at least mostly.
The down side is that if you make changes to the original parts, you have to remirror them - they don't update. But it only takes a short time to do it. I've tried it a few times and it's not a bad method.
WT

I just got the same message after editing a sub assembly. Very straight forward, no mirrored parts. I had to open some of the components of the sub ass'y, move the roll back bar up and down again, then save and close. I then regained access to the assembly. I remember seeing this back around 2001 but have never seen it again till now.