I have resolved this issue with the help Disposable Hero and colleagues in the Discord Channel. It resolution is stated in the fix links, be sure to check carefully. In the permissions link above, Ian from Navigraph refers to the Usercfg.opt and to ensure the last entry in the file shows the path to you Community Folder. I had checked this, but not closely enough as it was pointing to the Localcache not to the Community Folder. Once changed, everything worked! If this issue suddenly occurs to you, I strongly recommend this is your first port of call to resolve.
Regards,
Keith