Introduced in Macrium Reflect v7.1 a timeout is now applied to VSS. This prevents backup jobs from hanging indefinitely and causing scheduled tasks to queue forever if VSS has an internal problem that causes the VSS snapshot creation to stall.
The default time out is 15 minutes, however, on some systems that are experiencing heavy disk I/O during snapshot creation this may not be long enough and you may experience the following error in the log:
VSS Timeout - Retrying without VSS writers
First try simply rebooting Windows to clear the problem. If that doesn't help then increase the VSS timeout value.
To increase the timeout value create the following registry entry:
Timeout in seconds, e.g,
Note: If you are unable to resolve the problem by increasing the timeout value then this may indicate a serious problem with the VSS subsystem. To troubleshoot this further, exclude VSS writers by selecting the Other Tasks menu, then selecting Edit Defaults and Settings... In the Reflect Defaults and Settings, select Advanced Settings then VSS Settings.