After converting from 4.7.6 to 4.9.1 specific maps won't open and will crash the editor with a D3D11 error. This has been reported by multiple users but has not been reproduced internally.
Google Drive project link:
1. Download project from Link in description (this project was created in 4.7.6 and converted to 4.9.1)
2. After project opens go to Maps/Viking_Campaign folder in content browser
3. Double click on 1st_Quest_Part_Four map
Editor crashes while trying to open the level
Head over to the existingAnswerHub thread and let us know what's up.