I never had this problem before, but what Windows system do you have? Do you have XP, Vista, 7, 8, or 10? It could be a compatibility error. If that is the case right click on the RPG Maker you are using and go to compatibility mode and chose one of the Windows mode to run the program in. That might help
what was placed in the dropbox? A single installation file (blue 3D-cubus/hexagon as a symbol) or a directory with several folders (in that case, the exe's symbol would be a dragon's head)
Please tell us what was the reason so this doesn't become yet another "I got solution" thread without an answer.
I'm kind of curious.
Oh, sorry!
Even though I allowed the program through my firewall, it was still blocked. I right clicked on it and went to properties. At the bottom, I clicked "unblock."