In Eclipse you "install" JDKs/JRE's into Eclipse's
Java inventory. See the Window/Preferences/Java/Installed JREs menu/dialog sequence. "Installing" means that you define a name that points to where the corresponding JRE is located on your local filesystem.
In your project, you have the option to use the default JRE or to select one of the other JREs. In the case of this particular project, it appears that a specific JDK/JRE was configured and that the name of the JRE that was requested does not match any of the names defined in this installation of Eclipse (RSA).
You have 2 options, based on what examining the currently installed JREs tells you.
1. Find an equivalent installed JRE and modify the project to use it.
2. Install a suitable JRE on your computer and create an entry in the Eclipse JRE inventory under the same name that the project expects.
Either of the above will trigger a project (and possibly a workspace) rebuild, so it's a good time to brew a cuppa after you've made the change.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.