I have written a mobile application in java. It uses file-operations, so i had to sign it with a certificate (to do not disturb the user with security messages). The application works fine without signing, but the signed jar says "Invalid application" when i run it.
I have bought a certificate from thawte, so it have to be good (and i got help from online chat support to install it, so it is good). The mobile (Nokia 3110 Classic) includes the thawte root-certificate.
Can anyone tell me what is the problem?