Blender UPBGE Black Screen

Hello everyone, I have a problem. which I cant find out what happened.
I made a little game about StarGate with DHD, when I hit the P key everything works fine, but when I try to make an EXE Runtime file and try to open it, it’s open but the screen is black and the cursor is not movable. Sounds works, so I tried to unpack and pack again all into Blend file. but still no luck.
Strange is: that another project I made also in UPGBE 3 based on Blender .2.92 works perfectly.
It looks like my player camera isnt as default camera , but it appears only in exe runtime file. not in the embedded player or standalone player. Please help. Thank you and If someone already try solved that, take my apology. Thank You

you would have much more success finding help posting in #game-engine sections. the bge has been removed from blender and upbge shouldnt be considered supported by official support.

EDIT: also, your obligatory “its alpha!” upbge 0.3.0 is experimental and shouldnt be expected to be stable and/or production ready. this is also where posting in games section is good as that is where all the upbge devs hangout