unable to connect to Projector

As far as the Mac is concerned, a projector is just another external display. Use an external display with your MacBook Air - Apple Support describes what to do. Unfortunately HDMI communication failure is not something easily diagnosed; it either works or it doesn't.

Be sure to research your Epson projector's documentation. Perhaps its HDMI port has to be explicitly selected... that sort of thing.

What is its exact model designation?

What happens when you mirror displays according to your setitngs? Does the projector see it then?

Does your projector have an on screen input menu that its remote or on device buttons can pick HDMI as input?

Is the project showing a light in its projector lense? If not, make sure the projector is warmed up, and that the projection light is not blocked by any shades.

kobus261 Said:

"unable to connect to Projector: My Macbook Air is unable to connect with Epson Projector through an HDMI cable, although it does detect the projector, I cannot display anything"

-------

Use a 4K HDMI cable.

Open System Settings, and then type the word display in the search bar. Is the projector seen?

Screenshot: