Today I decided to update all of my mods to the KSP 1.9.1 versions, and when I attempt to load my save file I am asked if I'm sure I want to load the save, because several active vessels are missing certain parts.

Some of these were from NearFutureSolar, and I found this issue on the Github page for that particular mod, and I solved the problem using the advice found there. However, one of these missing parts is called KspiEpstein, and I can't seem to find it anywhere.

Can anybody point me in the right direction here? I just want to load my save file in the latest version of KSP, but now I'm having to hunt down multiple missing parts from multiple mods.

the are 2 possible solutions, either you do some save game editing (replace old name by new namne) or you simply make a clone of the existing parts with the name of part you are missing.

Thank you... I was able to edit that config file and use the old name, and that resolved the issue. In the future I will probably edit my save & craft files with the new name so as to avoid this issue in future updates. Much appreciated.