The spooler alarm message "messages expired from in-queue, age over ..." indicates that messages are expired due to their age.
This alarm reflects the number of messages that have been stored in the spooler database for a longer period than the specified Message Lifetime (see the Setup tab), without being transferred to the hub.
In this situation we need to investigate the reason for messages being queued at the robot. If this is a normal occurrence, you may need to consider if the configured message expiration time should be increased. The default is 7 days, so you could try increasing it to 14 days as a test.
These messages originate from from low-level file handling, and may have multiple causes. If unable to write to the file system, this can for instance be because of a full file system, or file system corruption or interference from anti-virus scanning/programs.
On some operating systems, disk problems may result in the file system being set to read-only, which will cause this type of messages as well.