Hi @Stephen_Harris,
Please see our documentation on this at the following link:
https://help.roonlabs.com/portal/en/kb/articles/faq-i-m-having-trouble-setting-up-my-nas
Use SMBv3 when possible. Failing that, SMBv2 should also be ok, but do not use smb2 with large MTU as it has known compatibility issues with Roon. If you’re using a Synology NAS and running your Roon Core on macOS, you can find some more information about fine-tuning your setup here
Don’t enable AFP or Timemachine if possible – some users may need this functionality for other applications, but they’re not needed for Roon. You can find more information about why AFP is not supported here
Hope this helps!