If I understand your question correctly, the user is trying to access Sage 100 via an RDP RemoteApp, with Sage 100 installed on-premises on their network, and Sage 100 Workstation is published as an RDS RemoteApp (terminal services).
In this setup, no PC emulation software (e.g., Parallels or VMware) is required, as Sage 100 runs on the Session Host, and the user accesses it remotely. Depending on their network configuration for the RD Web server and RD Gateway, the user on a Mac should be able to launch the Sage 100 RemoteApp using the "Windows App" (formerly Microsoft Remote Desktop app, available in the Mac App Store).
If the RD Gateway is configured to allow external access, the VPN may not be necessary. If not, the user will need to connect to the company's VPN first before accessing Sage 100.
Alternatively, if the RD Web Client (HTML5) is installed, the user may access Sage 100 via their browser. In this case, the browser running on their local device (Mac) doesn't have any specific limitations since Sage 100 runs entirely on the Session Host, including any required browser components like Edge. However, note that browser-based access might have limited functionality compared to the native Remote Desktop app (e.g., printer redirection or clipboard integration may vary).
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George Khairallah
CTO / Co-Founder | gotomyerp / Zaptiva / CFOTech
george.k@gotomyerp.com | 877-888-5525
https://gotomyerp.com------------------------------