OTA update hangs during TWRP patching

On my Motorola Moto z play the todays update to https://images.ecloud.global/dev/addison/e-0.7-n-2019071716984-dev-addison.zip is hanging since ~1h on the TWRP stage “patching system image unconditionally”.

Do you have any suggestions what I can do to not loose all my data and restore a working OS?
Please help.