Colin: Thanks for this. I had tried messing with the internal zip file structure and that broken PNG, but only with exporting and importing which hosed any internal connections on assemblies so was a pain and it was not viable except for very simple singular projects. Input/experiences:
In my case, even a very old file from way back in this thread was in the cache without me having to do step 0 so that was good. However, I did run into some projects that were not in the cache. Adding to offline cache put them there. In the case of a duplicate named file, I could tell if I had the right one from the 0 size small.png. For every cache file I found missing, simply choosing add to offline cache per your instr added it back to the F folder, or updated it's date.
From experimenting, I found that my shortened version of your instructions below worked, no need to go off-line and back for example.
I even found a broken project where it had externally linked assemblies and even one that needed updating. Process fixed it, too, without losing any links etc!
I found you could append .zip to the cache file, edit with windows explore and remove the .zipwhen done. But, 7zip is free so I installed it to make this easier but and no file renaming.
I had multiple "userID" folders in the cache path, I picked the newest one Mine was:
C:\Users\[me]\AppData\Local\Autodesk\Autodesk Fusion 360\[FusionID]\W.login\F
In summary, my shorthand process using your solution was:
The minimal fix (from Colin's instruction details) that worked for me:
Open the cache folder in one window,
Open Fusion in another.
1. In Fusion, find a broken thumbnail project, and in the cache folder find the corresponding .f3d. If not there, in Fusion right click on project and add to offline cache
2. Open f3d cache file with 7zip, navigate to 0 size png and delete
3. In fusion, open file, make trivial change, (I hid and unhid anything in the tree), close file(which saves it).
DONE.
That fixed the thumbnail in Fusion and on their online website.
3 Simple steps, Fixed. SWEET
VERY NICE DETECTIVE WORK, you did what no one else has managed. I've fairly quickly fixed every one of my broken projects.
Kudos.
Scott
