Why Wont My CC Merge?

So I am trying to streamline my CC by merging it. Technically RE-merging it, as I have had to redownload a number of CC. But when I try to merge the packages, Studio will only merge a few of them. I have tried smaller batches than I usually do, but even with only a dozen CC it is failing. There is nothing wrong with the CC, as they work fine unmerged, but I have so many they are making my PC chug. I am running the most current version of Studio. Any suggestions for what I can do about this?