On Windows, if you run one build from one directory, shutdown, and then run another build (or the same one) from a different directory, you will get a string of nsComponentManager errors, and apprunner will not launch. If you launch again (twice in a row) from the same directory, it will launch fine. If you go back to the first directory, you will experience the same sequence of events. You should be able to go back and forth between different builds without experiencing this type of difficulty.
It is me!
*** This bug has been marked as a duplicate of 4965 ***
verified as a dup
Moving all Apprunner bugs past and present to Other component temporarily whilst don and I set correct component. Apprunner component will be deleted/retired shortly.