Project created in 4.12.4 won't open in 4.12.5

I’m fairly new to game development so there might be an extremely simple answer to this, but my project won’t open after I installed the 4.12.5 update.

How do people normally deal with updates on big projects?

edit:

This problem is actually a little more complex than I thought and I have no idea how to describe it. Basically, if I get so far into a project the editor crashes with no error. When I try to start it up it gets to 70% and then crashes again with no error. There are no compiler errors.

I somehow managed to fix it (i have no clue how I did it, or if it just managed to fix itself?) and now it runs again.

The only reason I even update this post is because I have no idea when it’s going to crash again, and I have no idea how I’ll fix it.

Edit again:

It was because I added a constructor to my game mode class. Removed it and problem solved.

Hello,

Typically, it is good practice to delete your Saved and Intermediate folders before upgrading to a new version. However, keep in mind that upgrading a project to a newer version is always a risk, as it is possible that some assets will no longer function properly.

So try to delete the Saved and Intermediate folders and see if you are able to get the project to open. If not, please provide the logs from your project’s Saved->Logs folder and I’ll see if there’s any information in there that could clue us in to the issue that you’re having.