Plenty of bugs in 2021.3

Not sure what precisely is your issue (you can write them down stating all details here, so they can even be fixed within this version, and definitely for 2022.1), but the most useful tip: always make backup of your workspaces, even if you do not change versions of MCR. And if you change them, make backups your #1 rule. Although snapshots exist to find out if there are bugs, there will always be some elements that need fixing, and 2021.3 was huge update, also code-wise.

Hope I helped you a bit. As said, if you have issues, point them out precisely and giving as much details as possible on GitHub. Devs are looking there frequently and give feedback.

In 2021.3 there is this bug if you right anything in procedures it will just vanish after saving if you try to reopen it.

like it gets totally clear like this image

I used a plugin called Downloading and I don't know if it is causing the problem

This was the code in the plugin I have some modified

public class DT2Procedure {

	public static void executeProcedure(Map<String, Object> dependencies) {

		{
			try {
				URL url = new URL("");
				ReadableByteChannel rbc = Channels.newChannel(url.openStream());
				FileOutputStream fos = new FileOutputStream(""),
				fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
				fos.close();
				rbc.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

	}

}