iso file playback failing on recent copies

[themib]

Windows 7, latest version of DVDfab bluray.Up until recently I have had no issues. My problem 'may have coincided with either a DVD fab update or avast antivirus, but may not be related to either.
I have for many years bean able to create and successfully playback blu ray iso files on my home setup. Either 'full disc' or 'main movie' iso files. The last 8 disc I have tried have been un successful.
I get a message from my playback player ' file type unsupported.
The copies created as normal. they have .iso extension, I use image burn before the first fail as the write engine I have not changed any settiings. I have tried one disc again with antivirus uninstalled and still did not work.
Something is corrupting the isofiles during the copying stopping them playing. All previous iso file still play back ok. Can you please suggest something to try? or suggest what may have caused this?

[Dora]

themib
Is there pop-up region choosen window? Make sure select the right one.
What is your playback device?
Can you got the same message when you play 'full disc' or 'main movie' iso files?
Post internal log here, if burn to disc, also need burn_internal.log.

Try to disable GPU in setting- a/v codec.

[themib]

Hello Dora.
Yes correct region.
Playback device is an oppo bdp bluray player with a firmware that allows bluray iso playback.

I believe I have isolated the problem to the usb hard drive I was copying to.
I tried to another drive with success on two discs that had previously failed.

Strangly, discs attempted after the software update failed, but work on another drive.

I may copy the failed files to another drive but I dont think that will work.
"Can you got the same message when you play 'full disc' or 'main movie' iso files?" Yes I did, but I think its the hardrive.