Yes, all my Store items disappeared two days ago as well. Spent a full day fixing it. I moved my sims 3 folder to my desktop, then started up my game to get a clean folder. Then added everything back in one by one: saves, mods, what little cc hairstyles I have. All worked fine, so I redownloaded the Store content from my purchase history. That was fine too.
The last thing I added was my document with UserPresets. It is in the main folder and all that is supposed to be in there are your recoulered textures and patterns. But upon adding the UserPresets file, suddenly all my freshly dowloaded Store items disappeared again.
I got everything working bij deleting the UserPresets file, and all the .ebc files from the DcCache folder (these are the Store items). Then redownloaded the Store content. Haven't had any more issues since.
