Flint Silver, your problem may be related to your antivirus software. What are your computer's operating system and your antivirus ?
I encountered the same black screen problem with the free version of Avast on Windows 10. To solve it, I selected the "repair" option of Avast from its uninstall menu. When the repair was complete - it took less than one minute -, I launched GameMaker Studio 2 and my project. Then I cleaned my project by going into the Build/Clean menu. Then I ran my project. At this moment Avast may ask you if you want to authorize GMS2 to run. Of course you do ! Now your project should run finely - well, depending on the quality of your code ! You may have to repeat all the repair Avast/clean GMS2 process later if the black screen ever come back. I had to do it twice, but now Avast seems to be at rest with GMS2.