Hi. I cant install .jar files again on my phone it keeps giving the message 'Certificate error contact application supplier'. Did some research but solutions i got did not work. Software installation is on 'all' and online certificate check is 'off' which normally should solve the problem. Please help. Am using 6120c. It just started today. Infact i still installed .jar this morning.

Make a backup of ur contacts and other important stuff, then restore factory setting *#7370#
just do this as a last resort

Thanks. But obviously that would be the last resort. Funny thing is i can replace installed .jar files. I can also install .sis files. But to install new .jar is the problem

Just discovered something else. I can install .jar on phone memory, but gives error only when installing on memory stick

Create a new folder in da memory stick and install ur jar into da folder

6120c does not allow user to specify istallation folder. you only get two options. phone or memory stick

. .dat error, as i knw only occur while trying 2 install unsigned apps on s60 phones. .

unsiged applications will still install only that you have to give a cofirmation. the thing is .jar files that i still installed few days ago can no longer install.