Hopefully it either solves itself asap or you figure it out asap! It's so annoying when something like that happens. Makes you realize how reliant we are on those previews!
You'll want to look at your computer's HD space (vs. your EHD) since that's what I think "renders" the previews. I've researched this issue a ton and the biggest culprits are lack of overall local HD space and big files and/or those with lots of metadata (within the same folder). Is it universally happening or only with specific designers and/or files? With me, I could see some files and not others ... if that's the case it's 99% likely it has to do with the metadata on the files you have stored.I have about 350 gb left (of my 1 TB EHD). The file sizes don't seem too big
I wish there was an easy answer, but it's a huge PITB. You can either batch process resaving the files to smaller sizes (I created an action I ran on a couple kits, but it's not perfect and time consuming) or you can buy/write a script that does it. On the customer end, there isn't much else you can do to easily remove the metadata. Once most designers know this is an issue for them, they will buy the script so their products are easier to use. I don't think anyone has figured out why Photoshop saves a bunch of extra data for some users. I know it frustrates the designers when this happens to them, since their customers rely heavily on the previews!
