The cause: Here are two possible causes of the error:java: javactask: source release 8 requires target release 1.8:

-This error message appears if the code in IntelliJ IDEA was created using JDK 1.8 and was unable to find the appropriate JDK compiler.
-When the user inserts wrong Java compiler information in the code, this error also appears.

Solution:

Solution 1: Altering the Project Bytecode Version using the “Settings” Menu

1. Select the “File” menu from the Menu bar.
2. Choose Settings
3. Then you’ll choose and extend the “Build, Execution, Deployment” option.
4. Then, within it, open the “Compiler” option, and from the list, select “Java Compiler.”
5. You must adjust the “Project bytecode version:” set to “1.8” inside the “Java Compiler” window and click “Apply.”

If you use Apache Maven, try the following solution.

Solution 2: Including the Compiler Plug-in inside the “pom.xml” File

1. You will copy and paste the following code into the “pom.xml” file when you have accessed it.

   <build>
   
   <plugins>
   
   <plugin>
   
   <groupId>org.apache.maven.plugins</groupId>
   
   <artifactId>maven-compiler-plugin</artifactId>
   
   <configuration>
   
   <source>1.8</source>
   
   <target>1.8</target>
   
   </configuration>
   
   </plugin>
   
   </plugins>
   
   </build>

2. In IntelliJ IDEA’s Maven menu, after making any necessary code modifications, choose the “Reimport” option.
3. The project settings will be imported again.
4. The appropriate settings will then be applied by the tool automatically.