Fro some apps Like ucsschool.veyon.porxy i am recomended to update to a stageing version Available 999.0.0-staging
Why is this, and how can i remove/spesify the version?
You are probably using the test app center. The 999.0.0-staging version is an internal development version.
When installing, you can specify a version the following way:
univention-app install ucsschool-veyon-proxy="4.9.1.12-ucs1"
To deactivate the test app center, and return to the production app center:
univention-app dev-use-test-appcenter --revert