This is a pretty strange situation. It seems like somehow you have an empty string in the COMMANDS table, column ARGUMENTS. From what we can tell in the code, this should be totally impossible, since we always reject attempts to set this to an empty string (Null is ok).
Was this table manually modified?
What kind of database are you using?
To fix the problem, the following should work: 1) stop CM (sudo service cloudera-scm-server stop) 2) back up your database (just in case!) 3) log in to the database (see db host / port / database name / username / password in /etc/cloudera-scm-server/db.properties) 4) Run the following query: update PROCESSES set ARGUMENTS=NULL where ARGUMENTS=''; (note that '' is two single quote characters, not a double-quote character) 5) start CM (sudo service cloudera-scm-server start)