Do you have the two expansion packs for Roller Coaster Tycoon 2 installed along with your base game? Our servers occasionally have scenery objects and rides that belong to them and thus playing OpenRCT2 with just the base RCT2 installed instantly disconnects you from any server using those expansions.
If you do have the two expansion packs and still have this issue let me know if this issue persists, in the chatroom.
Get the expansion packs? You're gonna have to look for any digital copies on places like GoG, Steam and such, or maybe buy a physical copy, I guess if you can find one. The Deluxe pack, which includes the Base game + both expansion packs, is mostly on sale on GoG and Steam and go for only a few bucks.
If you meant the chatroom, there is a link on the bar above you that leads to that chat room. Or, go to this link: http://chat.manofteal.com
Do you have the expansion packs installed for Vanilla RCT2? If they show up in your vanilla game, then OpenRCT2 should work the same way. If you've just installed the expansion packs via their respective executable setups, OpenRCT2 should reflect that change the next time you open it.
To see if the game acknowledges your installations you can simply see in the new game scenario window if any and all expansion pack scenarios show up in their respective tab.