Laura Green - 2010-03-19

Hiya,
Trying to install clearantlib but getting this error
C:\apache-ant-1.7.0>ant install
Buildfile: build.xml

BUILD FAILED
C:\apache-ant-1.7.0\build.xml:26: java.lang.NoSuchMethodError: java.lang.Excepti
on: method <init>(Ljava/lang/String;Ljava/lang/Throwable;)V not found

Total time: 0 seconds
Press any key to continue . . ..

can anyone advise?