Gson NoClassDefFoundError after ADT and SDK Tools update to v17 Gson NoClassDefFoundError after ADT and SDK Tools update to v17 android android

Gson NoClassDefFoundError after ADT and SDK Tools update to v17


I faced a similar problem today.

This fixed it for me:

  • Remove all Android Library projects and external jars from the build path.
  • Create a folder named 'libs' in your project.
  • Place all external .jars in that folder, the ADT should now place them under 'Android Dependencies'.
  • Re-import all your previous Android Library projects the normal way.

The issue is that external jars are not placed in the 'libs' folder by default when using Properties - Java Build Path- Add External Jar, instead they are placed under 'Referenced Libraries' instead of 'Android Dependencies' and this causes the NoClassDefFoundError.

Please, check Dealing with dependencies in Android projects for more details.


  1. Right click the project, and choose Properties
  2. Go to Java Build Path-Order and Export.
  3. Tick 'Android Private Libraries'
  4. Click Project, Clean


For SDK Tools 17 you need to rename your library project's folder from "lib" to "libs" as suggested here.Also have a look at this.