[Milhouse]

i could not identify the exactly build for you.

Well, now you can - see links in my post.

It shouldn't take long to confirm if the problem is in the last Kodi 14 test build, or not (if it is, try some older Kodi 14 test builds to be sure). If the last Kodi 14 test build is OK then work through the Kodi 15 test builds until the problem appears.

Knowing if this is a regression or not is useful but comparing OpenELEC builds with some-other-operating-system build is not so helpful, there are too many differences. Knowing when the problem started makes a fix much more likely.

Uploading a sample file will also help - it could be an encoding issue.