I have 4 large QTVR (QuickTime VR) files, which are displayed correctly QT Player 7.4.1 on old Mac. But they are transformed to movie format on QT Player 10.4 on a New Mac.
How can I repair/avoid this ?
QuickTime VR hasn't been used for at least 10 or 11 years so it's going to be really difficult to find a current player for this file format. There's likely no path to remedy this.
Even on Apple's website, it's listed as "legacy/historical". This piece of documentation was updated in 2009 - 8 long years ago.
From a 2016 Business Insider Article: The inside story of Apple's forgotten project to change how we explore the world from our computers
When Steve Jobs returned to Apple, QuickTime VR was de-emphasized. Apple put out its last QuickTime VR-specific press release in 1997, although Apple continued to use it to provide 360-degree views of new products like iPods as late as 2006. "Quicktime VR all really happened in that Scully window before Steve came back, and I think that Apple does not pay any attention to the stuff that happened during those years," Bohrman said.
There may be some open source or 3rd party applications that support it, but going off Wikipedia, the list is quite small.
You need to install QuickTime Player 7 for Mac OS X v10.6.3 or later from this link:
I can confirm that I can still interact with my QTVR files, both panoramas and Object Movies in macOS Sierra.