Issue

When trying to run a project in Studio Pro, it fails, and an exception resembling the following is generated:

System.NullReferenceException: Object reference not set to an instance of an object.
at Mendix.Modeler.Deployment.CoreMetadataWriter.WriteMetadataProperties(lProject project, JsonWriter writer) in Mendix.Modeler.Deployment\CoreMetadataWriter.cs:line 55

Environment

Studio Pro (all versions)

Cause

When the MxAdmin user does not have an administrator user role associated with it, this null reference exception is thrown.

Solution/Workaround

To resolve this issue, ensure that the MxAdmin user has an admin user role associated with it:

1. Navigate to App Security > Administrator tab.
2. Change the User role property to a user role with the System.Administrator role (refer to our Administrator documentation for more information)

Additional information 

• Mendix documentation: Administrator