Calling the function with the syntax from the function header causes the game to crash
[<text>,(<title>,<buttonOK>,<buttonCancel>,<icon>,<parentDisplay>)] call BIS_fnc_3DENShowMessage;
I removed the brackets instead and spawned the function, which works fine.
[<text>,<title>,<buttonOK>,<buttonCancel>,<icon>,<parentDisplay>] spawn BIS_fnc_3DENShowMessage;