Hi Sinan,
It could be a widget that's not functioning properly, or a microflow running synchronious and taking too long to finish. When it takes too long to finish, the connection between the client action and server might interrupt. Causing the user to see an error, but the function will complete on serverside, so there won't be anything in the application console logging.
This is both only visible in the console log of the browser, can you ask the user to give you this information?
Hi Sinan,
You can inspect the browser when the error occurs and check the error in browser console and check what are the widgets used in the page or if nay js action are being used itn he app and narrow which one is causing the error