Error building project. Very important!!

[rober_sin_t]

Hi everyone

Sorry if this isnt the correct forum to post this question.
I'm new in the JDE, i have been able to build some projects but not this time, i have been looking on the internet but i havent found anything, this is the error code:

java.lang.NoSuchMethodError
at net.rim.a.a.b.do(Unknown Source)
at net.rim.a.a.b.a(Unknown Source)
at net.rim.a.a.d.a(Unknown Source)
at net.rim.a.a.i.a(Unknown Source)
at net.rim.a.a.i.a(Unknown Source)
at net.rim.a.a.i.a(Unknown Source)
at net.rim.tools.compiler.c.e.a(Unknown Source)
at net.rim.tools.compiler.Compiler.v(Unknown Source)
at net.rim.tools.compiler.Compiler.a(Unknown Source)
at net.rim.tools.compiler.Compiler.compile(Unknown Source)
at net.rim.tools.compiler.Compiler.main(Unknown Source)
I/O Error: java.lang.NoSuchMethodError
Error while building project

it seems to me that there is a lost library or something but i have no idea. Any help?