X7123M3-256

https://en.wikipedia.org/wiki/List_of_game_engine_recreations

Are you sure that's RCT2 and not RCT1?

The directory you want to select is the one that contains rct2.exe and the "Data" and "ObjData" folders.

This is caused by missing expansion objects. Do you have the expansions installed?

OpenRCT2 supports Mac OS 10.14 and above. If you're on an older version you would need to either update your OS or use the release version of OpenRCT2 (which still supports older Mac OS for now, but the next release won't). If you have trouble downloading the vanilla game files from Steam, you can follow the guide here, or use the demo version which also works.

Here is what the homepage looked like. The sign up link is in the top left corner above the search bar. You won't be able to access it or anything else on the site until it comes back online.

Either delete one track and rebuild, or use a script to change the ride ID for all the track pieces belonging to one ride (this might be something the plugin system can do, IDK) There is no built in facility to make two rides into one. Another option is to keep them as separate rides but use a track merge to connect them. This will probably only work if you disable the block system.

Select "object selection" from the cheats window. This will allow you to edit the ride selection.

Yes, you can do this. In fact, the prebuilt wooden design "Great White Wail" makes use of this trick. In order to make the lifthill not count as a block, remove the chain lift from the topmost track piece (the gentle slope to level). It may take some experimentation to get the timing right.

If you are talking about the custom RMC track type, that is done with a modified version of the game and will not work with the official version. The source code for that is available here. Lots of people build RMCs by either layering steel track (typically twister or LIM coaster track) on top of wooden coaster track using zero clearance, or building wooden supports underneath with scenery. You can look at the recent Deurklink contest for examples of RMCs built in OpenRCT2.

It should work with RCT Classic.

The "download all" button will look for the missing objects in NE's database, and if it finds them there it will download them automatically. However, the NE website is currently down, so that feature won't work at the moment.

Yes, this is still a work in progress, and in fact I'm working on it right now. The binary build that I linked is a month old, and quite a bit more has been done since then, but I estimate another month until completion. The end goal is to get the custom track merged to develop. That's the only way it will be "regularly available" since custom track types require a modified OpenRCT2 executable that is otherwise not compatible with the official game, and this isn't really practical for widespread use. I make the code available for people to play around with, but I don't expect anyone to replace their existing OpenRCT2 install with this one anytime soon.

The Github page that you posted a screenshot of (the first link I posted) is for the source code, not the precompiled binary. You use that if you want to build the code from source. If you want a precompiled binary, you won't find it on that page - the openrct2.exe executable that's in there was last updated in 2015, and honestly I don't know why it's there, but it's certainly not what you want. The precompiled binary version can be downloaded from this link instead, as I said previously. This was compiled by someone else about a month ago; I know that several people have downloaded this and had it work but I haven't tested it myself. For this version, all you should have to do is unzip and run openrct2.exe.

That link is for the source code - you can download either the source or the binary but obviously, source code needs to be compiled before use - my comment above assumed you were using the precompiled binary build. You can find build instructions for all supported platforms here - the procedure is no different, but I will need to send you the latest set of track sprites so you can build g2.dat (they're not in the Git repository because they are updated so frequently).

If you downloaded the binary build, you just unzip it and run openrct2.exe. You will need to enable the "allow arbitrary ride type changes" cheat in order to see the custom track, as there is no custom train that uses it yet.

The custom RMC train is available from here. You can download it an install it by placing the .DAT file in your OpenRCT2/object folder. The custom track requires a modified OpenRCT2 executable; it is not a custom object. The latest source code can be downloaded from here and there is an older Windows binary here. This is still a work in progress and it is obviously not compatible with the regular OpenRCT2.

It's not in the JSON file, it would be in the source code somewhere (probably in RideData.cpp but I haven't checked). Changing it is definitely within the scope of OpenRCT2 but if it was indeed this way in vanilla I'd question whether it's really a bug; you could open a PR for it and see what they say.

No it doesn't. He used a modified version of OpenRCT2 where the shirt color would be set based on the weight of the guests, in order to easily visualize the guest weight for the video. It doesn't work that way normally

Can you upload the save file?

If you get this error message, it's not because you are missing the RCT2 files; the game crashed. Maybe try a different version?

I made this 10x10 RMC this evening A video was uploaded here.

In the ride construction window there should be a blue flag - clicking that will display a ghost train which will run through the course continuously until you click the flag again. This pretty much removes the need for the "test unfinished ride" feature - I wouldn't be surprised if it has been removed (but I can't confirm that - they might just have moved it somewhere else).

Transport Tycoon has a well established open source clone (OpenTTD) and they're working on one for Locomotion as well (OpenLoco), but I don't know how far along that is. I am not aware of anything like that for Zoo Tycoon.

An updated screenshot.