Hi
please check if you can find some more details or useful information in the SMcore logs.
then as reported in the documentation
While performing backup operations with SnapVault or SnapMirror update enabled, an error might be displayed stating that a Snapshot copy could not be found on the destination storage system.
The issue occurs when the plug-in performs a query for the destination Snapshot copy while the status of the SnapMirror or SnapVault operation is pending idle.
Corrective action
You must include the following parameters and specify the value in the appsetting section of the SMCoreServiceHost.exe.Config file located under SmCore in the SnapCenter Server.
<add key="SnapmirrorRetry" value=retry_value/>
<add key="SnapmirrorTimeout" value=timeout_value/>
The value assigned to SnapmirrorRetry defines the maximum number of checks that can done to identify whether the SnapMirror is transferred. The value (milliseconds) assigned to SnapmirrorTimeout defines the time lapse after each check.