This will happen when the system goes into sleep mode or due to poor network connection. Please try out the following :

   🠊  Close the Apps4.Pro Migration Manager App if already opened.

   🠊  Stop the Apps4.Pro Migration Manager Service and Start it again. (To open Service Manager console, type services.msc in Run box).

Note : Please be cautious of the parallel tasks(if any) running in the same machine. Restarting the service will end these parallel tasks too.

   🠊  Open the Apps4.Pro Migration manager App.

   🠊  Click F12 to open Dev Tools page - Right Click the refresh icon near address bar and Click “Empty Cache and Hard Refresh” - Refer Image