I just finished working on a file for a client and saved it to the compressed zip folder that it was sent to me without decompressing. Photoshop seemed to save to the folder without problems but when I went to go to open it again, my work was gone and all that was there was the original file. Did PS save my work someplace else and not tell me, or was it not saving at all despite not giving me any permissions errors? Help!
Photoshop cannot save into a compressed zip folder.
If you double-clicked the file your operating system will have unzipped it into a temporary folder then sent a copy to Photoshop. A subsequent File - Save will have just saved it back into that temporary folder, NOT into the zip file. The good news is that (on Windows at least) the folder should still be around somewhere.
Have you looked in your File - Open Recent menu? You may just be able to find the name there and re-open it.