It sounds like you have tried quite a few things to solve the problem but you didn't mention that you followed the instructions in the Knowledgebase article about bad key file.  There might be something there that can help.

Thank you Richard, yes I have also followed that article completely, as well as removed the antivirus, confirmed option 5 is disabled, re and re'd the software from scratch - no joy. Activation is successful and Quantum then immediate fails to open post activation. Event ID 1026 .NET runtime has an unhandled exception error, followed by an application error ID 1000, both listed below

Why does it work fine until activated? I find this curious..

Note that when activated these changes are happening in the "C:\Users\Public\Public Documents\Sage Software" directory per the KB article saying files are missing

C:\Users\Public\Documents\Sage Software\Simply Accounting\2024\1 has two new or updated files simacct$.dat and simply.cfg

C:\Users\Public\Documents\Sage Software\Simply Accounting\Logs\2024 has one new file Sage50_N_203-10-17_1.log and this only logs startup and shutdown events.

that is the extent of the changes post activation per the files date/time stamps.

ID 1026: Application: Sage50Accounting.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.NullReferenceException
at Simply.Domain.Utility.RegisterData.ReadSimBusKeyFile(System.String)
at Simply.Domain.Utility.RegisterData.ReadSimAcctData(Boolean)
at Simply.Domain.Utility.RegisterData.ReadSimAcctData()
at Simply.Domain.Factories.SalesCodeVersionFactory..ctor()
at Simply.Domain.Factories.SalesCodeVersionFactory+NormalVersion..ctor()
at Simply.Domain.Factories.SalesCodeVersionFactory+Enterprisebuild..ctor()
at Simply.Domain.Factories.SalesCodeVersionFactory+NormalVersion.CreateNormalVersion()
at Simply.Domain.Factories.SalesCodeVersionFactory.CreateSalesCodeVersion()
at Simply.Domain.Factories.SalesCodeVersionFactory.get_Instance()
at Simply.UI.Start.SplashScreenUI..ctor()
at Simply.UI.Start.SplashScreenUI.DisplaySplashScreen()
at <Module>.DisplaySplashScreen()

ID 1000: Faulting application name: Sage50Accounting.exe, version: 31.0.0.1, time stamp: 0x650544ba
Faulting module name: KERNELBASE.dll, version: 10.0.20348.2031, time stamp: 0x3af8fc2f
Exception code: 0xe0434352
Fault offset: 0x00138d52
Faulting process id: 0xc48
Faulting application start time: 0x01da028153cf6192
Faulting application path: C:\Program Files (x86)\Sage 50 Quantum Accounting Version 2024\Sage50Accounting.exe
Faulting module path: C:\Windows\System32\KERNELBASE.dll
Report Id: 733e7172-69e4-4add-8a21-3bfa929b6461
Faulting package full name:
Faulting package-relative application ID: 

I've never figured out where the license info is kept but when you search Bad Key File, there are several messages on these forums that talk about clean uninstall and having to do some manual deletion and registry cleaning.

It's likely that you will have to get Sage Tech support involved in this.

Update for anyone interested - we removed the entire RD 2022 server and rebuilt it from scratch, adding only windows updates, MS office 365 and Sage 50 Quantum, the results are exactly the same, Sage, once licensed,  is dead and fails to open.

Fixed - we were given a bad serial number, yes that's all, it allowed the install and activation on that bad serial number but then it dies with no explanation it just fails to open. It makes no sense why it would activate if all info is not correct. Glad it's fixed, but frustrating.

Hi Paul_R ,

Thank you for detailing the issue you're experiencing with Sage on your new Windows 2022 terminal server. I was unable to find your account details with us based on your profile here but feel free to email me the details here to forward onto the team.

Here's a quick rundown based on this article's content:

1. Connection Manager: Ensure that the Sage 50 Connection Manager is installed and properly configured to bind to the TCP protocol. Verify IP/Hostname resolution is correct.

2. Firewall Settings: Make sure the necessary ports and processes are allowed through your firewall for Sage 50 to operate correctly.

3. User Permissions: Right-click on your Sage data folder and adjust the sharing and security settings. Test accessing the data from various workstations.

4. Service Log On: Add the local server administrator (not global admin) to the Log On tab for the Connection Manager Service. Restart the service and test.

5. Local Permissions: Navigate to 'secpol.msc' and add network users to the User Rights Assignments.

6. Network Cards: If the server has multiple network cards, disable all but one to test the connection.

7. Re-examine .NET Install: Since you mentioned a suspicion about .NET, it might be beneficial to completely uninstall and reinstall it, even if the repair showed no issues.

If you've already followed these steps and the problem persists, we would recommend reaching out to our support team. 

For further assistance, you can consult our support resources at  www.Sage.com/Resources or phone 1-866-996-7243 during regular business hours.

Hope this helps!

Warm Regards, 
Erzsi

We are an IT provider this as a client setup, so you would not have found an account under my profile info. Thanks for reaching out, it was resolved per my post.