I use MyEclipse with a local app server quite often for debugging. I love how it can insert changed code into the JRE without restarting most of the time. When it fails to replace code, it used to alert me and give me the option to stop or restart the server. I must have checked the "don't show me this again" box or something, because the dialog never appears, and I can't seem to find out how to reenable it...

No worries. Window> Preferences > Java > Debug > "Hot Code Replace" > Show error when hot code replace fails

i have been using eclipse for a long time.
i want to know the funda of hot code replacement.
i mean how does it do, dies it repace class file in tomcat or .....
i want to do it for new object also.
so that i can place new object at runtime and start working without stopping and starting.
Regards
Hemant Nag

Thank you! I kept looking under the run/debug area...