I got new laptop, so I moved all my files, reinstall B4A, sdk etc..
I loaded my old keystore to the b4a, put the password - all ok
but when I tried to run the app, (from the IDE - press play)
it gave me message on my devide - something like, signiture has changed, reinstalling old app, and installing the new one
1. Why?
2. Will I be able to publish new apk now?
3. Will all my users will get this message?
The signature has somehow changed. Are you sure that you weren't using the debug key before, or a different keystore file?
You will not be able to upload the APK file to the market if the signature is different. You can try uploading it and see if the signature is really different.