No, you shouldn't actually see those. You can hide them by setting error reporting to none in your global config, but you shouldn't see them in the first place even if your server is configured to show them.
Did you update hotspots from an old version, or did you start by using the latest one? When you go in the database to the #__hotspots_marker table do you see the customfields column?
Is anyone else seeing these errors?
2 years 4 months ago #31261