First of all, I'd like to point out that I am aware that this question has been asked countless times and I am aware of the usual solution. However, it doesn't seem to work for me.
When the error Exception in thread "main" java.lang.UnsupportedClassVersionError: org/telegram/mtproto/state/ConnectionInfo : Unsupported major.minor version 52.0 occurs, it is generally caused by compiling with an incompatible JDK-JRE combination. However, as shown by the images below, my setup seems to be in order:
Fig. 1. JDK Compliance
Fig. 2. JRE Setting
Fig. 3. Java Home
What seems to be the problem? What am I missing? I'm using Eclipse Luna, trying to run some Telegram API Layer 11 code (the code works I reckon, as it was used by others).
The JAVA_HOME environment variable is irrelevant to how Eclipse will run code, as far as I'm aware. Likewise the compiler settings you've shown for a project don't affect how code is run.
Instead, you need to look at the Run Configuration you're using when you run it, and check the environment there. Make sure you're using Java 8, and all should be well. Click on the triangle next to the Run button, and select "Run Configurations..." to open the dialog with all the settings. Then look at the JRE tab, and ensure you're using the right JRE.
i see that you have a 32bits JDK version for the JDK 1.8 and a 64bits version for the JDK 1.7 i you running your project on a 64bits machine try to use the 64bits version of JDK 1.8 Note: you must have a 64bits version for eclipse too
来源：https://stackoverflow.com/questions/23624038/peculiar-eclipse-java-lang-unsupportedclassversionerror-unsupported-major-minor