Today at 23:00 the Matrix server will be offline for maintenance until approximately 23:30.

Edit (23:40): The upgrade is over and took a bit longer tha anticipated because the database upgrade (PostgreSQL 11 to 13) was slower than anticipated because the database has grown since the last upgrade of this type. 

If you experience any issues, let us know in our support room or via mail to zedv@physik.fu-berlin.de.