Save as problems

Libre version 5.1.5.2
I initially posted a question about remote server access.
The reason for that question was using ‘save as’ to save to a FreeNas server was not easy, then stopped altogether.
Now the ‘save as’ function has stopped working to the desktop.
An error message comes up to say there is a write error.
Have I got a problem with the software or is there some problem in the method I am adopting to save the work?

Please try resetting the user profile, sometimes solves strange issues.
https://wiki.documentfoundation.org/UserProfile
Usually it’s enough renaming/deleting the file “user/registrymodifications.xcu”, it affects all the options in Menu/Tools/Options, and the files “user/basic/dialog.xlc” and “scrip.xlc” are overwritten, additionally custom colors in “user/config/standard.soc” are lost.

It is not an answer! In spite of the solutions suggestions above I still have a problem using “save as”. The proram does not reposnse and I have to cancel it.

This is the Libre Office version I’m using:
Versie: 5.1.4.2
Build ID: f99d75f39f1c57ebdd7ffc5f42867c12031db97a
CPU Threads: 4; Versie besturingssysteem:Windows 6.2; UI Render: standaard;
Locale: nl-NL (nl_NL)