I think you saved my day. in the error message it was said that sometimes the project has to be cleaned. So I cleaned it and it worked!
I wonder why F5 doen not clean the project at the same time ?
(I am using a device)
Thanks a lot
1. The compiler tries to reuse all kinds of things between compilations to make the compilation and deployment faster. This is why it doesn't "clean" the project automatically.
2. The compiler doesn't know that you have uninstalled the app from the device. So you need to clean the project (Ctrl + P) to force it to build everything.