Transcend Portable Hard Drive Issue

Try it on another pc, it's probably a bad sign (and a disk from a bad batch).

Freezing is no good.
I've had a couple portable hard drives which started freezing at some point, tried formatting but the problem persisted. They both turned out to be physically damaged. The nature of portable hard drives, I guess. Never bought another one, not reliable.

It usually means the HDD is dead. Either physically or the file table portion got damaged/corrupted, so Windows does not know how to interpret the data.
It can also be some bad media files or too many of them; generating the thumbnails can take a lot of time, even on Win10.

You can try to access it through a traditional file manager (https://freecommander.com/en/downloads-portable/), but maybe you need to drive a drive health check on it. Use the built-in WIndows one or one of the more popular freeware options (HD Tune, CrystalDiskInfo).

Probably about to die, check it with one of the apps talgaby mentioned and try backing up what you can.

If you're on Windows, look in the event viewer for disk errors. Also, check the manufacturer's support/download, they should have some diagnostic software.

did you run a dskchk and errchk for the drive?
instructions may vary.

If the portable enclosure has problems, formatting the drive will not solve the problem. If you want to try and save the data, I would remove the enclosure and plug the drive directly into your computer as a second drive through SATA (with the computer powered off of course). If that still doesn't work, you can try formatting it, but I would not trust the drive again and I would make sure anything important is backed up someone else if you continue using it.

I have never used external SATA, so I don't know how it works, but if you are using a laptop with a eSATA port (could be powered or unpowered), you may be able to connect the bare drive that way (if you have the correct cable/s) instead of opening the laptop (if the laptop will even accept a second drive internally).

Have you tried something like Testdisk that uses skips OS and directly access disk?

Really powerful tool, but definitely not easiest.