OJS 3 author unable to submit revision

Hello, we have a few authors that are unable to submit revisions in the Review stage.
They have received an email from OJS informing them that a revision has requested by the journal editor. Once they click on the link and log in OJS, they receive an error message “you don’t currently have access to that stage of the workflow” and the page won’t load. I have attached the error message below.
I have checked one of the authors’ role in OJS. He is a reader, author and reviewer.

I have also checked PHP log files and find the following error log

“PHP Warning: file_put_contents(\\cache\fc-pluginSettings-2-defaultthemeplugin.php): failed to open stream: Permission denied in \\lib\pkp\classes\cache\FileCache.inc.php on line 90”

Does anyone have any idea as why this is happening?

Many thanks,