Warning about blender file conflicts and compatibility solutions

• Blender often doing changes in .blend files structures due applying new functions, etc. but not informing to much about these changes in blender, and news realizes (in case of new versions, etc.).
• Due this many .blend files are broken (around GUI, configuration or other problems that made project are broken and blender crashing).
• Other problems around Blender making situation that user want new version, but then must back or other case.. that impacting for project
• This is more complicated around other blender distributors like UPBGE, K-Cycles, LuxCore, bforartists, blendercam and other with new render engines and evolutions

The proposal is to build some solution for .blend file compatibility, eg.

• .blend file structure version as compatibility information as additional information around blenders versions (when open and saving)
• user must know the line of .blend file structure version for line of blender versions to safe backward usage of files and forward if saving files in other blender versions (this is the most popular case that making problems for users and developers around issues, coz user forgo-ting about situation that changed blender version and saved by new old files, etc. problems with auto save)
• Blender must inform user about situation if saving .blend file in other .blend file structure version as compatibility information compared (must be included in .blend file and easy to check by user and blender, eg. Blender bottom belt)
  • Blender software version 3.0.1
  • Blender file version 2.8-3.0, 3.0-3.1
  Then in belt:
  • 3.0.1 /2.8-3.0 or 3.0.1 /3.0-3.1
  • / separating software version/file version
  • can be more |
  • 3.0.1 |2.8-3.0 or 3.0.1 |3.0-3.1