If you got an error "certificate expired" or "certificate error" while installing Theme, Software or Game:
1. Disable certificates in Tools -> App. Manager, choose Options -> Settings and set Software installation to All and Online certif. check to Off.
2. Try to install Theme, Software or Game. If failed - read next.
3. Go to 'Tools -> Settings -> Date and Time' and change phone date a few years back (at first change 6 months back, then if failed - change 1 year and more back).
4. Try to install Theme, Software or Game.
5. If failed again - change phone date 6 months forward, and then if failed - 1 year forward.
6. Try to install Theme, Software or Game.
7. Change date to current date.
8. If it does not help, then try to sign the file on https://www.symbiansigned.com/app/page/public/openSignedOnline.do
9. Otherwise the application got old and need certification update from the developer. This application harldy can be installed.
Other installation problems:
1. If file has SIS or SISX extension, then, as a rule, it is not supported under different Symbian operation systems, meanwhile such files are usually supported by both 3rd and 5th Edition.
2. If file has JAR or JAD extension, then, as a rule, such JAVA applications are supported by all Symbian versions.
