Error: Unable to activate the window with this title

The bot is getting failed and creating error as "Unable to activate the window with this title(com.automationanywhere.botcommand.data.impl.WindowValue@53434088). Verify that the window is opened.", this is only failing whenever the bot takes more time means more than 4 hours to execute and it is getting failed at the last subtask used to update the data in the output file(Excel File), and when we check the screenshots they were black.