System extensions were a common source of instability on the Macintosh, as third-party code was of variable quality and would often patch the system in ways that did not always work correctly. Some extensions didn't work properly together, or worked only when loaded in a particular order. In addition, different extensions might try to patch the same part of the system, which could lead to extension conflicts and other instability. Tracking down these sources of trouble was another task most Mac users encountered at some point. Troubleshooting Mac OS extensions could be a time-consuming process of bisecting and trial and error.