Affected version(s): 7.10.5 or later
You are trying to update your Open-Xchange Appsuite installation to 7.10.5 (or later) and get an error message after adding the new repository:
Err:1 https://software.open-xchange.com/products/appsuite/7.10.5/backend/./ InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 12111537DFD4BCF6
With the release Open-Xchange 7.10.5 we also rolled out a new cryptographic key for package and repository signing, using future-proof cryptography and comply with upcoming platform requirements. In order to update packages from software.open-xchange.com it is mandatory to deploy and trust the updated public key.
Install the new key, see https://oxpedia.org/wiki/index.php?title=Importing_OX_Buildkey
STATUS: updated documentation