52104: RtdNotification: Mismatched GCM sender IDERROR: 52104error-52104 page anchorERROR Error - 52104error---52104 page anchor RtdNotification: Mismatched GCM sender IDrtdnotification-mismatched-gcm-sender-id page anchor Possible Causespossible-causes page anchor Credentials configuration or clients application configuration are wrong. Possible Solutionspossible-solutions page anchor Validate you use sender id and Api key for the same application from google developer portal.