On 07/28/2020 Firefox released version 79 of the browser.
This version has an incompatibility problem with the Plugin of said browser.
It does not allow the inspector or activities like Clic to interact with objects within an iFrame.
This caused all my robots (6) to fail for the same reason.
Return Firefox to version 78
Turn off automatic browser updates.
We have to wait for @UiPath to update the plugin.
Versions used to test: