Ops Manager v4.2 EOL This Month
MongoDB Ops Manager 4.2, released in August 2019, is End of Life (EOL) as of 31 July 2021
If you are running a version of Ops Manager prior to 4.2.24, you will need to first upgrade to this version: Upgrade path to Ops Manager 4.2.24
Once upgraded to 4.2.24, the next step is to upgrade to 4.4: Upgrade path from 4.2.24 to 4.4