ECUFlash and Romraider use different formats for definition files, they are both .xml but the content is different so you can't mix and match.
Try downloading all the latest ECUFlash and Romraider ECU defs:
Romraider Defs:
https://www.romraider.com/forum/topic360.htmlECUFlash Defs:
https://www.romraider.com/forum/topic3808.htmlOnce all your definitions are in place try opening the file again.