Unable to Instantiate Activity: ClassNotFound Exception

Question

I'm suddenly unable to run my app due to this error, where the ClassNotFound refers to my main activity class. It happens on my phone as well as in the emulators. This is an existing stable app that's been around for quite a while, and I haven't made any code changes since the last time it was working a couple of weeks ago.

The only recent changes I've made is that I started a new project in the same workspace and updated the Eclipse components to SDK Tools V19 and SDK Platform Tools V11, plus updating the Eclipse plug-in as indicated.

Any ideas at all of what suddenly broke here?

Answer 1

Create new folder "libs" in the project and copy all the External Jar file files in this folder.then Right Click on Project -> Properties->Java Build Path->Here Change the Path of Jar files to "Libs" folder and remove the path of extrenal jar files that you have given from computer path.After That it will Work.

Note:if there is already folder "lib" in your project then only change the folder name "lib" to "libs".

Answer 2

Try cleaning the project: Project->Clean