how to solve this error
It looks like you're using -source 1.5 and -target 1.5. LWJGL requires Java 8.
LWJGL requires Java 8.
Check the javac settings under: Settings -> Build, Execution, Deployment -> Compiler -> Java Compiler.
Quote from: spasi on September 28, 2016, 13:56:48
Check the javac settings under: Settings -> Build, Execution, Deployment -> Compiler -> Java Compiler.
thank you!