Thank you Revocado to reply here, despite I cannot see your post for some reason.
Whatever I tried, even removing and reinstalling Chrome, nothing seems to work. When there is no internet connection, I cannot use Construct 3.
Regretfully the offline feature is mandatory for me. This should be an issue which is top priority for Scirra because it makes Construct 3 useless and unreliable in locations with poor or no internet connection.
Maybe providing a "Load offline" or "Reload offline" version is a good idea. In this way we can make sure the offline version is correctly installed before we go to a location where there is no internet.
I hope Scirra takes this subject serious because this kind of failures are showstoppers.