From Forum Nokia Wiki

Review:

This article provides advice for fixing problems surrounding installation of midlets. The article is divided into various sections, each section discussing a separate class of problems. The article identifies symptoms, and then for each symptom discusses possible route causes and how these might be addressed. Quite a wide range of possible errors/problems are discussed, ranging from problems downloading a midlet, to application errors (exceptions), to the dreaded "invalid jar" message.

I think this is a useful article, especially for beginners who may find installation problems very confusing. It is nice for newcomers to the Java platform to be able to lookup the causes of common installation problems. Even as someone who has been programming for the Java ME platform for years, I still occasionally run into errors like invalid JAR. It's useful to have a central repository which contains common installation problems and their underlying causes. These errors can easily creep in for so many reasons. Even just renaming a Midlet class file can result in problems if you do not update the midlet name in your JAD file. Through the contributions of others, this article can be even more useful. A useful section to add might be one related to signing and installing signed midlets, as this can often introduce a whole new set of problems before a midlet can get installed and running successfully.

--Larry101 12:25, 30 September 2009 (UTC)