I had a merge replication with one publisher/distributer and two subscribers , everything worked properly .suddenly one of my subscribers crashed and went out of work ,I prepared it but after this I encountered with a problem That replication doesn't work properly with this Error message

Last Command: {call sp_MSgetreplicainfo(?,?,?,?,?,?,?)}

Error Message :The subscription to publication 'GsAdmin' is invalid.

Error detail: The subscription to publication 'GsAdmin' is invalid.
(Source: Merge Replication Provider (Agent); Error number: -2147201019)
Invalid object name 'sysmergepublications'.
(Source: OFFICE1 (Data source); Error number: 208)

This is very important for me to fix this error.Any kind of advise could be useful for me.
Please help me.

Thank you mehdi