Hello Nop-Templates team.
Trying to upload Prisma Theme zip package to plugins screen but the following error happens:
Access to the path 'h:\root\home\...\www\Nop420\Themes\Prisma\Content\css' is denied.
I granted read/write to Theme folder but error still occurs.
I guess you have upgraded nopCommerce to version 4.20.
In that case you should not have existing Prisma theme in the Themes folder.
Anyway most probably some files are locked in that folder, which should not exist if you have upgraded only nopCommerce to 4.20.
In that case you can manually upload the theme and the plugins on the server.
You can stop the site and then upload the files and all should be fine after you start the site.