While trying to use CTA 4.1  new PSD function loading in Affinity Designer  I get two errors :
 
Failed to open PSD file 
"PC\AppData\Local|Temp\CTA4Temp\PSD_Cache\Default(0).psd     The file was not found." 
and
Failed to open file
"C:\Users\Donald   The filed not found."

Designer will load and open followed by the above error panels.  Is it most likely an error in the program or my system?

Thank You

Are you using an official release of CTA 4.1? I too use CTA, however, I don't see 4.1 available. 

I used the update found under the help tap in CTA.  This took me to the update page.

This does indicate it is for Pipeline only.   So if you don't have Pipeline you may not see this update.

Could you share your screenshot?
I have Designed too, but it doesn't happen this issue.
Or you can pass this issue to Technical support.
https://www.reallusion.com/CustomerSupport/User/FAQList.html