You will need to upgrade your version of PowerShell.
Also make you you have an up to date version of .NET framework.
See also https://winscp.net/eng/docs/message_net_runtime_newer_than_currently_loaded

Using the latest version on Windows 7 64 bit software. Trying to batch rename files on a Linux box. I get the following error message:

1918-12-03-DRAUGASw-i5-8.pdf => 1918-12-03-DRAUGASw_2nd_ed_i5-8.pdf
1918-12-04-DRAUGASw-i5-8.pdf => 1918-12-04-DRAUGASw_2nd_ed_i5-8.pdf
1918-12-05-DRAUGASw-i5-8.pdf => 1918-12-05-DRAUGASw_2nd_ed_i5-8.pdf

Continue? y/N y

Error: Could not load file or assembly 'file:///C:\Program Files (x86)\WinSCP\Wi
nSCPnet.dll' or one of its dependencies. This assembly is built by a runtime new
er than the currently loaded runtime and cannot be loaded.
Press any key to exit...

This batch file rename function has been very useful in the past. I am logging on to the Linux site using port 21. I got the same error message when trying to batch rename files using a port 22 scp login. The problem seems to be on the Windows PC side.