There was an error opening the file Legal Reg Change Concept v2.xd (Error code: 86) This is not a valid XD document.
I am using XD Version 49.0.12.14 x64 (Starter) on MacOS Big Sur Version 11.6.5 (20G527). The files were created in XD and stored on Google Drive. Very frustrating to not be able to reopen files created by that application.