Not long ago I had an issue with the Toolbox not working. I couldn't place a fastener directly from it or by using smart fastener, hole series or whatever. I contacted support and the solution had to do with which folder it was saved in.
Upon installation, you are allowed to select where you want to save the Toolbox folder and since I like to keep my stuff together, I put it in the SolidWorks Data folder instead of the C: drive. Rather than reinstalling the Toolbox (or SolidWorks altogether), my support contact adjusted the settings of either the folder or the file so that it was also writeable and not read-only.
Unfortunately I didn't pay close enough attention at this point, but if someone has this same problem and finds out which you should change, feel free to post it here to help other SolidWorkers. As for the guys at D'Assault Systémes, maybe it's a bug or something, but might be worth having a look at it. It's a bit weird being given the option to change the save folder and then not have it working.