When I try to run my Android project(which was working fine yesterday) I get the “Your project contains errors, please fix them before running your application” dialog. But my project has no errors. I’ve had this problem before, and the solution was always to Clean the project, but this time it isn’t helping. The red X icon disappears from the project in the workspace, then reappears when I try to run it. Also restarted Eclipse so it rebuilds the project. Help?
Go to your .android folder and delete your debug certificate. In my computer it is in this path
Inside that there is a file name ‘debug.keystore’. Delete that,clean and try to build the project again. Sometimes this error is caused when the certificate expires.
There are a couple of reasons as to why this might happen. Give these problems / solutions a try.
Problem with your Manifest. These don’t always show up, so give your Manifest a thorough check.
Suddenly missing / moved libraries or other dependencies. Right click your project, choose Properties and check the tabs under Java Build Path. When you accidentally remove / move a library file, or any other file the app is dependent on, it can cause an error like this without showing up as an actual error. However in the Build Path screen it will show with a little error sign.
Problems with your R.java. I had an issue with this before where there was a corrupt value in the R.java file. “cleaning” the project didn’t fix it, but forcing Eclipse to rebuild the file due to me erasing it manually did.
Problem with a cached version of your app. This one is a real pain cause there are no pointers for it, but sometimes for some reason Eclipse decides to mess with a cached version of your app. This can cause anything from apps not working to apps showing images that have long been replaced by other ones or have been deleted entirely.
If the other fixes don’t work, try navigating to your project folder and removing the
/binfolder. After that, rebuild the project and try to run it.
I hope one of these works out for you.
This problem is occur some time when you replace new debug.keystore file with the old one.
delete deug.keystore may fix the problem