We all know we can't generate or save material thumbnail through Revit API. But we have the ability to modify material's assets properties through it. The problem is when ever we do that, the existing thumbnail saved location will be wipe out and won't be save again until user manually do some modification through material browser and save it. There comes a big problem here, if user didn't do that, they will always have blank material thumbnails in their material browser and have to wait extra time for material browser to regenerate them. It's very inconvenient and time wasting. I suggest the development team to implement some mechanism so that if the material is modified by Revit API, next time user open the material browser, the thumbnail will be regenerated and saved into document.
One other thing very annoying is ever since Revit 2021, the thumbnail save location is totally unpredictable. If the Revit file is created by other user, it will use previous user name create a whole new user directory for thumbnail saving under C:\Users directory. It makes user wonder if their computer were get hacked or not. This bug needs to get fixed as soon as possible.
