It is very likely the database is corrupted.

Try the following:

• Stop Xeams
• Rename /opt/Xeams/db folder to something else so it is not found at runtime
• Restart Xeams

When this folder is not found, Xeams will try to recreate and re-populate data. It will run slowly for a few minutes. The actual time depends on how far your emails go in the past.