do you use configurations? maybe you open the file in a configuration where the features are suppressed?
Nope, I don't think this is the case. I do have configurations on the part but they are correctly configured, and none of the features are configured to suppress ( I only have dimensions in sketches configured currently.) I will look into whether deleting the configurations solves the problem and then report it to my VAR.
Yes, intermittently since SW2004 (not every release). Never managed to force it to repeat but it does occur.
In my experience, If I have a release where this happens, there's also the random "undo the feature tree" bug where the model appears to undo itself (step by step, click by click) right the way back through the feature tree. I have to kill solidworks.exe if this occurs otherwise I lose the part file. Also impossible to force a repeat.
I haven't bothered to report them over the years due to the randomness of the bug.
I don't remember running into that. I'd ask if you noticed any similarities in the Parts where this happens, but I'm sure you've already thought of that.
At least they were suppressed and you could still open the part and un-suppress them, here it happened that I would come in the morning and the part/assembly was the same as a few days ago, completely had to redo a days work. This happened so randomly that we couldn't diagnose it or repeat it. Fortunately for me, one day the IT guy and I were working on a project and the next morning all the changes we gone, was a huge exoneration for me, I finally had proof and a witness.