Do you have the object(s) in the room?
Is the view in the right place (if you have one)?
Do the object(s) have sprites, and if so, are they set to visible?
Is there more than 1 room, and is the right room loading first?
Do you have a draw event for the object(s) but are not using draw_self() or draw_sprite?
If the game window does not appear you may have an infinite loop somewhere. Start the program using the debugger, and after a few seconds, press pause, and see if it stops in some area with loops.
Probably not, but only one way to know for sure. Please upload your project so we can take a look at it, that'll probably be faster than trying out random stabs in the dark one by one at this point as none of the common causes I can think of seem to apply here.
I ran your project in 2.3.0 and it showed up just fine. Try temporarily turning off Avast (which I see the tray icon for) and see what happens.
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There are some questions you're probably better off typing into Google than posting here and waiting for an answer from a game development community about a question regarding an antivirus product. This community has absolutely nothing to do with AV, so you'll be able to find the answer just as well as we would if we googled it for you. You'll get answers faster, in your local language (if applicable) and can be self-sufficient up to a certain extent by taking initiative.