You do not need to be making an ic to use the generic IC as a starting point. It allows you to assign the pins in a pop up by clicking edit pin labels in the inspector after you set the number of pins you want on your new part. You then have a completed schematic. Then once that is done you create your BB and PCB svgs and go into the parts editor and upload the new image for each view and assign the pins which already have the correct labels because you labels them when it was still an ic.
Also if you use the editor you should never ever ever open the Fritzing parts folder. You use the editor to export and import SVG images. You never have to open the fzp files or unzip fzpz files at all. If you edit the files Fritzing creates when making parts you are likely to run into these corruption issues and complaints of parts already existing etc.
I do not tend to upload a lot of the parts I create unless someone comes along asking for one that I already have. All of my parts are created for making PCBs and I have ZERO interest in Breadboard. I work almost exclusively with SMD parts so all of my parts are usually little green adapter boards or ICs in BB view and even sometimes just a copy of the PCB svg which is useless for BB view.
Even though I sound against a standard I feel a set of guidelines for creating BB svgs would be very useful for those interested in using Fritzing for the Breadboard view. It just doesn’t happen to be me since I use it for PCBs and making parts for PCB creation is easy as pie 
Generate Schematic using mystery part or generic IC, change the labels, create PCB svg, change PCB svg in the editor and assign the PCB pins. Done and off to the board shop.