If you receive the error
then the standard_conforming_strings parameter is turned on and you are using a JobScheduler version that expects this parameter to be set to off.
This parameter is turned on by default since PostgreSQL 9.1.
JobScheduler releases older than 1.10.7 expected that this parameter is turned off.
This behaviour of the JobScheduler was changed with release 1.10.7. JS-781 - "SCHEDULER-451 Database check failed, database is not useable" for Postgres if the parameter "standard_conforming_strings" is turned on Released See How can JobScheduler run with PostgreSQL 9-1 and newer? for more information and a workaround.