Compile error "Class file has wrong version 52.0, should be 50.0"

Question

I'm trying to compile my project in IntelliJ IDEA. I'm using a class in an external JAR file and on compilation receiving the following error.

Class file has wrong version 52.0, should be 50.0

I understand that it's saying the JAR file was compiled with a newer Java version than that which IntelliJ is using. How do I make them compatible?

I have updated the Java on my Mac to 1.8 and when I run java -version or javac -version it confirms this.

What am I missing? (Apart from Java development experience)

Danu

You should check sdk configuration in your project(inside intelliJ) - maybe there you still are using old version - it depends on you configuration – Decorator

Did you get the solution? In my case I switched to using java 7 and everything works. – Chromaticity

"You are trying to run/reference a class compiled with JDK 8 using a runtime/compiler JRE/JDK 6." Check the accepted answer - #29907159 – Snuff

This is still an issue with intellij 2020.2 trying to switch from java 8 to java 14 – Darky

I got this error when I was trying to run Spring boot 3.X on java 8. Spring Boot 3.X is compatible only with java 17 and above. Hope this finds someone in need. – Selfsuggestion

Answer 1

Select "File" -> "Project Structure".

Under "Project Settings" select "Project"

From there you can select the "Project SDK".

Frontolysis

If using Gradle, along with above settings, please also select appropriate Gradle JVM settings. For IntelliJ IDE, its under tab: "IntelliJ IDEA" -> "Build, Execution, Deployment" -> Gradle, and update the Gradle JVM under "Gradle Projects" – Silvasilvain

wondering how this steps order answer the question as is just a matter of use another SDK and not really what the question asked – Guanidine

Or, if you can't change SDK like in my case, then lower maven dependency of the library causing this error. I've had SDK 1.8_191, and I had to use TestNG 6.14.3, as versions 7.x caused this error – Antimere

Answer 2

If the error comes from an external dependency (Maven/Gradle), the version you imported requires a newer JDK. (e.g., you imported Caffeine 3.0.x which requires Java 11, but you are using Java 8.)

Solution: downgrade the dependency to the latest version compatible with your JDK.

Java version numbers can be found in Java class file wiki page (byte offset 6-7).

Tletski

Thanks! This explains why TestNG 7.6.0+ can't be used with Java 8. I downgraded the TestNG dependency to 7.5 and it worked. – Johore

I had a similar problem "class file has wrong version 61.0, should be 52.0" for using the fundamental org.springframework.context.annotation.ComponentScan class! For me changing the JDK/JRE version didn't solve the problem. Then I downgraded spring-webmvc dependency version from 6.0.2 to 5.2.6.RELEASE and it eventually worked. – Ichor

Answer 3

It means your Java runtime version is 1.6, but your compiler version (javac) is 1.8. To simply solve it, just advance your JVM version to 1.8.

But if you don't want to change the Java runtime version, then do the following steps:

1. JAVA_HOME= "your JDK v1.8 folder path", to make sure JDK is also v1.8 and use java -version and javac -version again to ensure it
2. Make sure IntelliJ's compiler mode is set to compliant with v1.6. But I have tried that. It didn't solve my problem.

Latterday

"it means your java runtime version is 1.8, but your compiler version (javac) is 1.6. To simply solve it, just retreat the java version from 1.8 to 1.6." - rather opposite – Dealfish

I corrected the answer according to the @KrzystofWolny's comment. See also https://mcmap.net/q/152643/-is-jdk-quot-upward-quot-or-quot-backward-quot-compatible – Camorra

Re "It didn't solve my problem.": What is that supposed to mean? Why is it in an answer? Doesn't the last part of the answer work? Why is it included, then? – Spectroscopy

Answer 4

Check the version of Java it is showing in the error:

• 45 = Java 1.1
• 46 = Java 1.2
• 47 = Java 1.3
• 48 = Java 1.4
• 49 = Java 5
• 50 = Java 6
• 51 = Java 7
• 52 = Java 8
• 53 = Java 9
• 54 = Java 10
• 55 = Java 11
• 56 = Java 12
• 57 = Java 13

Install/download that JDK in program files/Java folder.

In Eclipse or STS, right click on project → Build Path → Libraries → add JRE system libraries → add the version of JDK showing in the error as an alternate JRE.

Beliabelial

Answer 5

Generally this kind of error happens when you try run a .class file which is compiled with another version of Java.

In your case, it is compiled with Java 8 (major version -> 52) and you want to run it with Java 6 (major version -> 50).

Here is a list of major versions of Java and SE version: Class file format major versions

To solve the problem, use the same version of the compiled class file, based on your project structure. In IntelliJ IDEA: Menu File → Project Structure → Project → Project SDK

In case of using builder tools like Maven, this configuration also should be changed in the corresponding settings. Here is an example of how it is done in a POM file:

<properties>
    <java.version>11</java.version>
    <maven.compiler.source>${java.version}</maven.compiler.source>
    <maven.compiler.target>${java.version}</maven.compiler.target>
</properties>

Unipersonal

Answer 6

I have got the same error as in the header because of a failed attempt to compile my project with Java 8 and then reattempting to compile with Java 6.

Some classes where compiled at the first attempt with Java 8 and did not recompile with Java 6. Mixed classes did not compile then. Cleaning the project solved the problem.

This answer is not strictly relevant to the question, but it could be useful for someone.

Cumuliform

Cleaning project did not do the job for me. I just removed the classes, which were throwing the error and did a clean build to get them compiled by 1.6. This resolved my issue. – Weintrob

Answer 7

I am using JDK 1.8.0_131 and For my case, the version code <version>2.7.5</version> in pom.xml and module -> language level 8 solved my issue.

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.5</version>
        <relativePath/>
    </parent>

Oaxaca

Answer 8

If you are using javac to compile, and you get this error, then remove all the .class files

rm *.class     # On Unix-based systems

and recompile.

javac fileName.java

Mcatee

Answer 9

The error signifies that you may have the dependencies that are compiled in Java 11, but you are using Java 8, so there are two options left. You can either migrate to Java 11 or ask the library developer to provide you with a Java 8 build.

Earpiercing

the versions you mentioned are wrong. It should be 8 (52.0) and 6 (50.0) instead of 11 (55.0) and 8. – Camorra

Answer 10

I also faced the same issue. The issue may be because Spring Boot and Java version are not compatible. For example, Spring Boot 3 need minimum JDK 17, so if you are using Java 8 then you have to downgrade your Spring Boot version to 2.*

Does Spring 3.0.x support Java 8? In Spring Starter I found sourceCompatibility = '17' default for 3.0.x and above

Tice

But for Spring boot 3, I have installed java 8 and its working fine in Eclipse without any problem but not in IntelliJ why? – Vibrator

Answer 11

Class version 52 is Java 8. You need Java 11.

Raillery

Answer 12

I installed a new JDK version, but I forgot to set the JAVA_HOME environment variable to the new JDK. Setting it to the correct version helped!

Estabrook

Answer 13

I couldn't change an SDK version, so I had to lower maven dependency of the library causing this error. I've had SDK 1.8_191, and I had to use TestNG 6.14.3, as versions 7.x wouldn't work.

Antimere

Answer 14

Project's build.gradle file:

allprojects {    tasks.withType(org.jetbrains.kotlin.gradle.tasks.AbstractKotlinCompile).configureEach {
        kotlinOptions {
            jvmTarget = "1.8"
            apiVersion = "1.8"
            languageVersion = "1.8"
        }
    }
}

Enneastyle

Answer 15

If you are creating your own JAR file, make sure that the application in which you are importing the JAR file has 'id' in the plugins section as 'application'.

plugins {
    id 'application'
}

If both JAR and application has 'id' as 'java', we might see a similar error.

Medarda

Answer 16

For Java 8 spring boot compactible version is 2.2.6.RELEASE

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.6.RELEASE</version>
        <relativePath /> 
    </parent>
    

Nottingham

Answer 17

This nonsense still persists in 2024 in an IntelliJ kotlin project. I tried everything in the already given answers, but there's now a new way of getting the error:

Despite having everything set correctly in both "Project Structure" and "Build, Execution, Deployment" -> "Gradle" -> "Gradle JVM", my project still compiled to a newer java version than my target system could handle. The solution for me after hours upon hours?

Change your build.gradle.kts to use the correct toolchain, in my case

kotlin {
   jvmToolchain(17) // I can't run 18 atm.
}

Vange

Answer 18

If the issue is in IntelliJ, then do this in the terminal (not in the IntelliJ terminal):

1. change the Java version to an appropriate one (in my case, using JDK 1.4 as the issue was class file has wrong version 55.0, should be 52.0)
2. java -Dspring.profiles.active=test -jar build/libs/<jarname>.jar
   Run this

Diverting

can you be more specific about <jarfile> argument? If my error is bad class file: /usr/share/openjfx/lib/javafx.graphics.jar!/javafx/application/Platform.class class file has wrong version 54.0, should be 52.0 Please remove or make sure it appears in the correct subdirectory of the classpath. then is the jarfile graphics.jar? – Gaylagayle

Answer 19

I have solved this by changing my pom.xml file:

<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.6.4</version>

Change 3.0.2 to 2.6.4.

Turkestan

Answer 20

I faced the same problem, "Class file has wrong version 52.0, should be 50.0" when running Java through Ant...

All I did was adding fork="true" wherever I used the javac task, and it worked...

Iridotomy

adding fork = true in configuration didn't work for me. – Cambrel

Answer 21

In your IntelliJ IDEA, find file tools.jar. Replace it with tools.jar from your JDK 8.

Gharry

Don't do this. The accepted answer is correct, and all kinds of weirdness could result from this alternative. – Langill