Jymn

I was having this problem, but I did eventually get it working, hopefully this helps: In the GOG galaxy app, on the rollercoaster tycoon deluxe page, under the Extras tab, there is an option to download "offline backup installers", I did that, then told the rct.exe to run in windows95 compatibility mode, then ran it (the RCT deluxe program) for a moment just to be sure, then tried linking again in OpenRCT and it worked