A while ago I merged all my gameplay mods into one package and it was working just fine, I could even edit and remove mods in the package if I wanted to, I added some new mods to the package and went into the game with these new mods in the package which were working just fine, but when I wanted to open the package I got this weird error massage which made me not able to edit or even check anything in the package because after clicking ok the package shows a new empty package, I have no idea what it means so I really hope you guys can help me with it.

pretty sure it means it is corrupted. this is why i am always against merging packages.

Aw that really sucks :\ Guess I will have to start all over again, thanks for you help tho.

No prob. Technically the Sims3pack does the same thing in the dccache folder. And I have a couple of those large files completely corrupted that they crash S3PE whenever I just open them. I'm not entirely sure how they impact the game, as it still loads fine. I suspect some CCs in there simply won't show up.

I recommend merging only in small packages. However, if you are using SSD or even a RAMdisk for your CCs, merging is completely pointless as SSD/RAMdisk small byte random read is like hundreds times if not thousands faster than HDD. This is the reason why we don't defrag SSD drives, it is pointless. In essense, having 1000 small packages files won't load any slower than 1 huge file containing those 1000 small files on a SSD/RAMdisk since there is virtually no file latency.