//does it have to depend on the filetype? does it make a difference if it was used for all files?//
Yes, it depends on the file type. Try the command and let me know how it goes.
You may try copying the entire DCIM folder to a USB flash drive and use the import wizard to transfer files to PC.
This time on my galaxy s8 I have selected "This Phone -->Tranferring images" instead of "Transferring files". Alright so the error occurred once again.
Since the error occured during transfer of a picture I am going to use del "%temp%\acq*.jpg" /a and show you what is shown in my temporary folder.

As you can see from the above screenshot, all the .tmp files dont have .jpg associated with them. This is reflective of what command prompt shows as well.
So, the only command that I can use is del "%temp%\acq*.tmp.*" /a

As you can see the acq temp files have been deleted and is also reflected in the command prompt below.

I will proceed following your instructions in your last 2 posts -- "And then click "Try again" in the error message window"