Fixes for application problems
If you run into problems during the Netbeans start up process, you may find that renaming/removing the netbeans configuration files can help. Under Linux, Netbeans stores its configuration data in a .netbeans sub-directory of your home directory (notice the leading '.'). On Windows, the configuration data is stored in C:\Documents and Settings\yourusername\.netbeans (replace 'yourusername'with your system username)
When you next startup Netbeans it will create a new .netbeans directory with just default information - so you will need to remount filesystems etc that are used by your project.
Sometimes, you may need to try deleting any .nbattrs files in your project folders, in Linux do:
rm -f `find . -name .nbattrs`
On Windows, do a Search->Files or Folders and remove them all
Servlets, Tomcat and JSP's
See this documentation
I'm getting asked for username and password credentials.... (on Windows)
This issue usually arises when tomcat doesn't shutdown properly. To fix this problem, you need to shutdown netbeans and any tomcat servers that are running on the PC. You can usually do this by closing netbeans and then logging out from the PC. If this doesn't work, close netbeans and then kill all java processes using the task manager.
Firefox 3 uses sqlite to store data for user's personal firefox profiles. However, under Linux a Firefox crash or unclean shutdown may result in your personal profile getting corrupted. If you cannot use the forward/back buttons, type URLs into the address bar or access your bookmarks then its likely your profile is corrupt.
You may find that you need to do the following to reset your firefox profile - exit Firefox if its running, then from a terminal:
mv ~/.mozilla ~/.mozilla-old
Restart firefox and you should be back to a default configuration.
You could also try to recover a working firefox profile by using a snapshot
If you can start Firefox, but are unable to browse outside of the School, then there may be a problem with your proxy settings. Check the proxy configuration pages for more information.
There is a mozillazine article on the topic.
If Firefox crashes it may leave behind lock files - when you come to start Firefox again you may receive an error message about the profile already being in use or you may be unable to get Firefox to launch. Have a look for a 'lock' in the .mozilla/firefox/default subdirectory of your home directory. You can delete this - Firefox should then be able to startup.