This error has started to crop up. I'm sure it is something simple. Files deleted or something?
It looks like you have lost the parts from an update but not the database entries for them (many of the parts I recognize as being in parts updates after the release). The best bet is likely to back up all your parts and sketches then save a copy of the two user directories (just in case of problems so the data is available) and then delete them and let fritzing rebuild them and the parts database.
I also noticed that some of the parts in Fritzing's library actually won't work on a case-sensitive filesystem, because the filenames in the XML files use different capitalization than the file names in the filesystem. I already submitted fixes for a few parts, but there are many more.
Interesting! Yet another thing to add to the parts checking script ... I usually run on Windows and thus don't notice it. At some point a cleanup of the parts database will be in order, but doing so without breaking existing sketches may be exciting ...edit: Actually, do you have a reference to such a part? While I can probably find one, a pointer is easier.
Here's a commit with a fix that I submitted: https://github.com/fritzing/fritzing-parts/commit/f124bfab7cdcf63c93abc5dbcf17ae41bfc58c09
I don't really have a list of parts that have this problem at the moment, I just remember stumbling on that from time to time (mostly with the IC footprints). I suppose finding the problematic parts is the main work for fixing this, as fixes themselves are rather trivial.
Well I can help with that, as my python script is capable of scanning everything in core parts and reporting on errors (and there are a fair number). I'll look at the commit and figure out if I can detect the problem. Thanks!
I wonder if I had downloaded the files, imported them, then moved them. I ran a search for a couple of the files and there is nothing on the computer.
I recognize some of the file names, which were ones I had downloaded from the forum.
At least the 4011 and 4070 normal and subpart versions are now part of core and should be there. They were posted in the forums and then made it in to one of the parts updates. It may be worthwhile to click on help->check for updates as sometimes the automatic update check doesn't seem to work. Clicking on that should check and update the parts if needed from github.
A reinstall seems to have done the trick. There were errors while trying to check for updates and the last line said to try a reinstall.
At least there were no start up errors!