java.lang.NoClassDefFoundError with updated ADT

Recently, I decided to update Android SDK.
just after update, I found that one of my projects is not starting anymore.
Debug reported the following errors:

05-16 19:36:02.118: E/AndroidRuntime(16193): java.lang.NoClassDefFoundError: net.sourceforge.zmanim.util.GeoLocation

05-16 19:42:37.173: E/dalvikvm(16313): Could not find class ‘net.sourceforge.zmanim.util.GeoLocation’, referenced from method com.kosherdev.toldot.DisplayData.getOuput

solution I found here NoClassDefFoundError – Eclipse and Android

I used to add additional libraries by adding External jar file in Build path.
Seems that some changes appeared in new ADT. You need just place your external jar file in libs directory and that’s it.