Mostly related to IE extension of UiPath. You can check following things
-
Go to extensions in the Internet Explorer and confirm that the UiPath extension is available and enabled
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Go to Studio → Tools and check whether IE extension is installed or not
- If both are installed - Confirm that the private mode and allow access to URL in the details section of extension. Close the broser and try again
- Last - Try uninstalling the extension and reinstall again

