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Java – Unsupported class file major version 65

February 25, 2025January 25, 2024 by mkyong

When we compile our Java programs, each generated .class file carries a major version that indicates which Java version was used during compilation. For example, if we compile our code using Java 21 (major version 65), and then run the class file on an environment with an older Java version, we will encounter the error: …

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Java – Unsupported class file major version 61

February 24, 2025April 25, 2022 by mkyong

When we compile our Java programs, each resulting .class file contains a major version number. For example, if we compile our code with Java 17 (major version 61), and then try to run the class file on Java 16 or earlier, we will encounter the error: Unsupported class file major version 61. This situation often …

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Categories java Tags java class file, java error 3 Comments

List of Java class file major version numbers

February 25, 2025January 25, 2022 by mkyong

This article shows all the major version of the Java class file, for example, Java 17 (61), Java 11 (55), and Java 8 (52).

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How to check which JDK version compiled the class?

August 25, 2022April 22, 2019 by mkyong

Find the major version of the Java class file, and we will know which JDK version compiled the Java class. Below are some popular Java LTS released and their major version numbers. Java SE Major Version Hex 17 61 0x3D 11 55 0x37 8 52 0x34 If the major version of the Java class file …

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How to Fix “Unsupported major.minor version 51.0” on Java

February 24, 2025July 13, 2014 by mkyong

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Categories java Tags java class file, java error, jdk tools 5 Comments

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