Engine crashes when i try to open 4.18 maps in 4.19

Hello,
whenever i try to open a 4.18 map in 4.19 the game crashes… no matter what map i try to open… any idea why?

Hello,

We’ve recently made a switch to a new bug reporting method using a more structured form. Please visit the link below for more details and report the issue using the new Bug Submission Form. Feel free to continue to use this thread for community discussion around the issue.

https://forums.unrealengine.com/unreal-engine/announcements-and-releases/1410408-unreal-engine-bug-submission-form

Thanks