External hard drive has over 700gb of space, but showing scratch disk full anyway

[Carly22113762mvan]

I'm trying to use my external harddrive as scratch disk space on my mac, but when I open photoshop and select the external haddrive as the scratch disk, it shows it doesn't have enough storage, even though it does.

The other weird thing, is that it shows the same exact amount of storage my mac has available.

please help, i used to be able to use the hard drive but now it won't let me.

[Ged_Traynor]

Hi

How is the disk formatted

https://helpx.adobe.com/photoshop/using/scratch-disks-preferences.html

[J453]

If you restore your preferences using this manual method does it work correctly?
https://helpx.adobe.com/photoshop/using/preferences.html#Manually
If that doesn't solve it, you can quit Photoshop and put the Settings folder back. If that does solve it, I would like a copy of your settings folder.

[Carly22113762mvan]

I tried the manual method, did not resolve.