eclipse marks every new project with an exclamation mark
eclipse, java
Solution
Go to `Window > Preferences` and check `Java > Installed JREs`, problem is there...
When you change JRE/JDK, you should perform `Project > Clean...` to force rebuild, this should help.
This "Problems" view I was writing about
And check Shadark's suggestion about compliance level, 1.6 is what you want.
Check also your project `Java build path`
There are also project compiler settings if "Enable project specific settings" is checked these settings have higher priority.
Problem
My eclipse marks every new project with an exclamation mark. i tried the steps provided here: Unbound classpath container in Eclipse but no cigar. i was able to delete java 1.7 and add the old 1.6 but now i get this error: ``` java.lang.UnsupportedClassVersionError: klasse : Unsupported major.minor version 51.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(Unknown Source) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$000(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) ``` Exception in thread "main" im pretty much lost. java seems simply broken to me. maybe i should just reinstall it? /Edit: since some dont believe me: there is no problem with klasse.java (some other projects have some normal errors that i cannot bother and CSVAufbereitung has the error i had in klasse.java before i followed the steps above. (thats why i created this question in the first place) IMPORTANT: i just realized that i only have the jre1.6 installed while having jdk1.7 and jre1.7 installed. so when i switch back to 1.6 it wont work because i dont have jdk1.6 installed. silly me. but i would like to keep using 1.7 so the main question is: why is 1.7 not useable anymore ("Unbound")? Update: i found out that i can create 1.6 project and they will run without errors. if i create projects with 1.7 they wont run. if i then downgrade those projects to 1.6 they still wont run. since i want to use 1.7 this is quite nagging.