Error in Scheduling "OData exception occurred: System.Net.WebException:The request failed with HTTP"

[FarhanAhmedGetz]

When ever we try to create new job or try to change in existing  job , it is hsowing beloww error

In logFile RSPortal*

OData exception occurred: System.Net.WebException: The request failed with HTTP status 503: Service Unavailable

Status of existing job

SessionID: 80ecf2ae-2be5-48b7-a408-bc401f23f460

[0] -1056505856: COM error: System.Core, Sequence contains no elements.

[1] -1055784828: The database operation was cancelled because of an earlier failure.

[2] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[3] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[4] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[5] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[6] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[7] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[8] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[9] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[10] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[11] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[12] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

[13] -1055784932: The command has been canceled.. The exception was raised by the IDbCommand interface.

OK

When I create new schedule following error occured ( error snapshot is attached