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- The version of Source has been upgraded - in this case, Source will attempt to install the same plugin version that was installed in the previous version of Source; or
- The plugin version is different - if the plugin was originally installed from the online store, clicking Update will remove the old version and install the new one. Note that this happens only once when Source is opened for the first time with the new plugin version.
Writing your own plugins
To write your own plugins using .NET and C#, refer to /wiki/spaces/SC/pages/51643422.
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