I have this issue for a few days now. I install GTA5 on 16GB USB flash drive(ADATA UV100/16GB) and I play the game without any problem as long as I want(no texture problems, no missing cars, no missing save data or whatever). After I turn off my console(4GB kinect bundle) on the next day when I decide to play, the USB flash drive is no longer configured for XBOX and the GTA5 installation is missing of course, so I need to install the game every time I turn on my console. I don't know if it is a problem with the flash drive or something else, but any help or advice will be good. Thanks in advance :)...
When you first used you're flash drive did you configure it for Xbox only? Also, did a meesgae come up saying this devies meets all xbox requirements?
If you answered no to either of the questions above. That could be you problem. I had the same troubles with an old flash drive i was using. Got a Sandisk B35 SDCZ33-016G-B35 16GB USB Flash Drive from Walmart and i works great.
Looking for a Founder Crew for GTA V? Check out my clan thread http://forums.xbox.com/xbox_forums/general_discussion/f/433/t/1575658.aspx
Yes I properly configured the flash drive and did get the messages that the device meets the requirements. And the flash drive was just put out of the box.
I had the same issue with an old Rocketfish USB drive, and I also have the 4GB console. I got a Sandisk Cruzer Fit for GTA hoping it wouldn't have that problem and so far it's been fine. When I configured it, it said it didn't meet the requirements but that was likely the write speed, the average read speed for this drive is around 20Mb/s and that's the only part that's important. I don't know if this has anything to do with it, but I plug this new drive into the rear middle USB port, the old Rocketfish I used to plug into the front USB port.
For me the problems occurs with two of the rear USB ports and one doesn't detect the flash drive at all. So you assume that this is a flash drive problem?