@Peter.v Welcome to the Rockstor community.
I’m pretty sure that you have been bitten by a recent regression in the testing channel updates in the Rock-on subsystem which is trivial to fix but as of yet remains broken. We do have a pending pull request to sort it but this will require another release which is a non trivial undertaking.
For a fix you can easily apply yourself please see the following thread / post:
Hope that helps and sorry for the inconvinience, but this kind of breakage is inevitable in the testing channel updates but there is effort to try and avoid it as much as possible. This one just managed to squeeze its way in during a particularly busy time for the main developers.