I had the issue that after a migration of a Domino environment all users received error messages after answering meeting invitations.

The customer prepared 2 Ubuntu LTS 20.04 server with Kernel version 5.x for the new Domino environment and we moved the data partitions to the new servers, installed 12.0.1FP1 and afterwards the troubles started.

We checked all settings regarding the language settings, modified them, did some sessions with HCL Support but nothing helped.

Therefore we decided to switch over to an officially supported OS ( CentOS ) and hoped to solve this issue. Last Friday we moved over the data partition, installed 12.0.1FP1 and guess what >>

The problems didn´t occur any longer !!

Maybe it has something to do with the new Kernel of Ubuntu LTS 20.04 or any other issue but don’t use any unsupported OS although the customer is forcing you to go this way 😉