Unable to create Win32 apps in Intune

TMFoughty​,  Below are the possible troubleshooting I can think:

1. Check if you have required permissions
2. Try adding a temporary assignment before saving, if you are trying to save with already added assignment, remove and re-add. 
3. Issue with the .intunewin package? - Re-download the latest win32 prep tool and package it, check if any file names in the package has any unsual characters or file name length, and check if setup file exists at the root you specified 
4. Detection rule problem - Re-create the detection rule from scratch, try re-browse the MSI file, or ensure all fields are filled for File/ registry detections, avoid leaving optional fields half-filled and most recommended is try scrip based detection method (sign it if required)
5. Browser/session issue (surprisingly common), re-login and try again
6. Rare but could be Tenant/UI bug, upload the package using Microsoft Graph or PowerShell using Intune module

I've had this issue before. What worked for me is ensuring I have a privileged role enabled (Intune Admin or Global Admin), then reopening Intune in another tab and recreating the Win32 App. Maybe session ran out?

I have the same problem. 

This error is usually means missing required field that Intune expects to be present but isn't,

Try to Check the App Information Section, Also, check the intunewin file if it was created properly.

Best,  

Ahmed Masoud 

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