[bdLover2]

Based on your description, the problem is almost certainly NOT the .iso file (since it mounts and plays correctly). The issue lies in the physical burning process to the BD-50 RE (rewritable) disc.

1. Update your Blu-ray burner's firmware.
2. In your burning software (ImgBurn or other), force the write speed to 2x.
3. Try a different BD-50 RE disc (or a BD-50 R disc if you have one).
4. If still failing, try a commercial burning program like CyberLink Power2Go.
5. Test the successfully burned disc in your LG player. Remember that rewritable discs (BD-RE) are sometimes less compatible with standalone players than recordable (BD-R) discs. If it plays on your PC but not the LG, the disc type might be the final issue.