Updating Baseline

I've tried updating a baseline in P6 and even if I change one activity by 5 days I receive the following error message in the log file. Assignment remaining start date cannot be earlier than activity remaining start date. 

Does the baseline not get updated at all if there are errors or will it only not update the activities affected?

I've tried searching for the assignment remaining start date and I can't seem to find it, I don't really fully understand what the error message means. 

Thanks