Program crashes

I compiled my code right before the “For the More Curious …” part. The app instantly crashes everytime and I’m greeted with this error message:

               Caused by: java.lang.ClassNotFoundException: Didn't find class "" on path: DexPathList[[zip file "/data/app/"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]

How do I fix this?

Hm. That error message could mean a few different things. Can you post some of your code here?

I’d be interested in seeing your AndroidManfiest.xml and your QuizActivity.

  1. Make Space on Your Device

Mobile devices have limited storage, which can be reached at some point, but apps still have a tendency to crash if the situation is not handled. Therefore, you might run into this error although your device points a great deal of remaining storage capacity. Newer low end devices such as Moto E have 8GB of built-in storage and a big part is covered by the system. One of the best and simplest ways to free up space is to start uninstalling apps, but if you use music apps, then you might not be able to find where the files are being stored. In this case use an app such as CCleaner. Also, you can try using DiskUsage, particularly if you want to get a visual display of where all your memory is going, and it will visually display your files size and locations.

Make Space on Device

  1. Clear Your App Data From Time to Time

There is a button called “Clear Data” within the app’s listing in the App Manager. This button will remove user-configuration as well as the app if it were installed for the first time. A combination of “Clear Data” and “Clear Cache” is a one-two punch that never fails, but the only issue with the “Clear Data” button is that you’ll have to reconfigure the app. Besides, your particular app needs server settings or passwords, you’ll need that information in hand before you tap the “Clear Data” button, and once you tap that button, then it’s back to square one.

Clear Your App Data From Time to Time

  1. Don’t Use Different Network Types

Many android apps users have experienced an app crashing after changing their network connection to either Wi-Fi or mobile data. In fact, on networks change Apps won’t crash unless they are poorly coded. Most flagship phones such as Samsung’s Galaxy series have a built-in auto network switch feature to transition the connection switch seamlessly and minimize data loss, but some apps still suffer stability issues most of the time and people facing this problem for some years now and the solution to it is rested on the shoulders of developers and of course Google, the maker of Android. But, no one seems to have found an effective solution. However, you can prevent an app from crashing simply by making sure to turn it off first before switching to another network.

  1. Uninstall Apps

Uninstall those apps you don’t use or need; check your app drawer to find such apps. Keep in mind that improperly written apps can cause all kinds of problems for your Android device, and built-in troubles can range from storing important data like a plain-text file in your memory card to sullying your notification bar with regular updates that can’t be disabled.

Ethan Stark

I had a similar error. It had to do with renaming the file.

The book recommended duplicating the file and renaming it before working on the challenge. After I renamed it “geoquiz challenge” it stopped running.


Maybe you rename it can solve this problem , It’s not very difficult, @Jpae000 Do you know how to reset password for Windows , I’ve been having this tough problem lately.