First of all, I want to say that the most common language is Spanish, this and all the text that follows is translated by google translator, since I don't know much English, and some things may not be understood because of this, now yes, I say my problem.

When I uninstalled Java 8.X, and I downloaded Java 16.0.1, Forge did not open, or crashed, every time I tried to open it, it closed, and the minecraft logo or its window did not even appear, the only thing that happens , is that the minecraft launcher (official), starts forge, and then says, that an error occurred

The same thing happens to me in Forge server (here the image is in Spanish)

And I don't know what to do, I use Forge 36.1.0, do I have to go down to Java 8 again, or can I stay a little higher? Is there any solution so that I can keep occupying Java 16?

Thanks
 

Currently Forge supports Java 8-15.

There is nothing stopping you from having multiple JDK versions installed, as long as you are always referencing the proper version for the task. This will likely involve either specifying the full path to the java you wish to use and/or modifying your systems path environment variable.

https://www.google.com/search?q=multiple+jdks+on+windows