I've never tried installing Sage 50 on a Mac but I can tell you that in order for Sage 50 to work over a network, you have to be able to ping the server by name and you have to map the network drive using UNC path (server name) not an IP address. I would recommend you look for someone who has experience with Parallels in a network environment.  If you can resolve those networking issues, Sage 50 will probably work.

Stephen, you mention "over a network" Would Sage50 Quantum with Sage Drive be classified as "over a network" or is that actually in the cloud which would work well on a Mac using parallels? I'm guessing that with Sage Drive you could essentially access your company data from any machine with Sage50 Installed on it, correct?  

If you used Sage Drive to access the data, then you would install Sage 50 on your computer as you would for a single-user installation. Then you would open the company off of Sage Drive, so no drive mapping would be involved (avoiding the problem you're encountering). When you open the company from Sage Drive, the data will be copied to your local drive and changes will be synchronized back to the main database via Sage drive.

I would recommend you read the Sage City blog post What exactly is Sage Drive and why would I want to use it?. The post is from 2017 so some improvements have been made since then and sharing of Sage Drive now has the option of being multi-user for an additional charge. But it is still the most thorough explanation of Sage Drive that I have seen.

i have a big problem, i have parallels 9 installed on my imac and want to run a software programme called sage accounts, this programme needs microsoft .net framework 4 to operate but something is stopping it from installing so I cant run my programme, any help ?

That's a UK Sage program, so you're in the wrong forum, but I can steer you in the right area to get .net framework 4 installed. You'll probably need Aaron Stebner's .net framework cleanup tool: https://blogs.msdn.microsoft.com/astebner/2008/08/28/net-framework-cleanup-tool-users-guide/