I use the EasyEclipse distribution of Eclipse, the free (libre) software development environment. I just figured out how to fix an obscure error message:
Eclipse Web tools editors (2.0.1) requires plug-in "system.bundle" Eclipse Data Tools (1.5.1) requires plug-in "system.bundle"
When I would start up EasyEclipse (version 1.3.1 for Mac OS X, with Python, C++, Java, PHP and more support added), it would tell me that I had some outdated components, and offer to update them for me. But when I opened the menu item Help… Software Updates… Manage configuration, I would get the ominous error alert:
“The current configuration contains errors and this operation can have unpredictable results. Do you want to continue? [Cancel] [OK]”.
I wasn’t able to find documentation about this problem specifically. (My purpose in writing this is to help others benefit from what I learned.)