1. Nexus, the strange one.Sonic Mania, CD, 1 and 2 are all similar in that you just need to extract the Data file, rename or remove the Data.rsdk/Data.bin file and then run the game to get Data Folder Mode. Retro Sonic even works that same way, and it's even older than Nexus! The reason Nexus is different is that the files in the Data.bin file are encrypted, and trying to run the game in DFM without decrypting them results in the game crashing. This happens if one or all of the files are encrypted still, but that's what this tutorial is meant to help with as it's confusing to someone who wouldn't know this information.
2. Requirements:RetroED v1.5.0
Sonic Nexus (Download the Summer 2008 PC build version)
The Sonic Nexus Decomp
Once you have everything downloaded, feel free to move onto the main part of the tutorial!
3. How to extract the Data.bin file:
Open RetroED and open up the RSDK Unpacker.
Click on 'Select Data File'. This will open up a prompt from the File Explorer.
On the File Explorer prompt, make sure that the file type is not set to RSDKvRS and is instead set to RSDKv1. Select the Data.bin file after you make sure of that.
Before going on, if you click on the first line which says Data/Game/GameConfig.bin on the left file list and the Encrypted? box isn't checked, that means that you didn't select RSDKv1 on the previous file explorer prompt. If that is the case, go back and reopen the file and make sure it's selected. The files won't be decrypted if you don't do this.
From here, click on 'Extract Data File' and select a location for it to be extracted to.
Next move the extracted Data folder over to the Nexus Decomp's folder and make sure it looks like this. If you have the Data.bin file still here, rename it to anything else but Data.bin or move it out of there. If you're going to do any modding at all, also make sure you have a backup of the Data Folder anywhere in case you need or mess up something with the one in the Nexus Decomp's folder.
To finish the Data Folder Mode method, go ahead and make a mods folder here. This as it's name suggests, is where you're going to be placing the mods you download at. This is what the file directory should look like at the end of this:
You'll know if you did everything correctly if you see the window title having (Using Data Folder) added to it!
This isn't required by any means but if you'd like to play in widescreen using my 424x240 Widescreen mod, open up the settings.ini file. Find the line that says ScreenWidth=320 and change 320 to 424, then save the file.