Unable to edit saved files

Hi folks
I am looking for some help, I have used freenas as a server for a number of years, my memory of setting it up is hazy. I had a problem with connection tried to solve part of which I updated 11.3 U5. Spent some hours with resetting and following what instructions I could fimd, whilst I can see the contents of my storage disk (WD1Tb) I have been unable to save - delete files I can only copy.
Any help would be much appreciated. Kind regards
I have a PDF of the entries but this is not alllowed for the forum mail.