Have you changed anything?
Can you build locally (by just pressing the run button)?
Can you please provide the build logs
There is a breaking change within Mendix between Version 8 and 9. Longtime Mendix had provided some compatiblity modus, but it looks like that this service is over.
Because of the breaking change one parameter name in one of the JavaActions needs to be changed.
Please open the file <PROJECT_DIR>\javsource\mindspheresinglesignon\actions\MindSphereScheduledAccessTokenConnector.java
Search for a parameter called TenantParameter1
PLEASE CHANGE THE PARAMETER to Tenant and save your file:
Back in Mendix Studio Pro make sure to synchronize your filesystem.
Now you can restart your project and it should work.