The reason there is a freeze or a crash while simming at about 16-20 games into your season is because that is when the minor league season starts. It simmed ok with a clean unstall of MVP 12 because of the full focus on the minor leagues. The Phase # rosters are major league focused, so little attention has been given to minor leagues requirements for minimum functionality. Each minor league team has to have at least 20 players, with a full 5-man rotation, a closer and all starting line-ups positions filled. When your simmed season reaches the opening of the minor league season and a game where a team does not have the required roster requirements, it will freeze or crash. Check out your minors with MVPedit, fill all the required slots, then export the .mbe to MVP Baseball 2005datadatabase, if you want this roster as your default roster.
Start a new season and your sim should be fine. If you freeze or crash somewhere down the road, its probably the same reason, but caused by injuries and suspensions. This is the reason Total Classics modders advise you to turn off injuries and suspensions. Their rosters also also do not focus on the minor leagues, but that doesn't stop the dynasty game engine from attempting to play a minor leagues schedule along with the MLB schedule. I found that to be a common problem with rosters that are MLB-focused, and I have been playing this game since it was brand new. It is best to play MLB-focused rosters with injuries and suspensions turned off, once you get the minors fixed. I hoped this helped.