Installed Jres -

💡 Even if you have Java 21 installed, your IDE might be trying to compile code as if it were Java 8. After updating your Installed JREs, check Java > Compiler to ensure the "Compiler compliance level" matches your intended version.

💡 If your project shows an error saying it is missing a JRE System Library, right-click the project, go to Build Path > Configure Build Path , and ensure the library is pointing to a valid entry from your "Installed JREs" list. installed jres

A common mistake is pointing the "Installed JREs" path to a simple JRE folder rather than a JDK. 💡 Even if you have Java 21 installed,