After upgrading to a different version of ArcIMS, the ArcIMS Administrator cannot be opened and the following error message appears:
"[ERR0402] Open site error:
The site requested cannot be opened.
It is not compatible with the current version of ArcIMS."
The .jar files located in Program Files\ArcGIS\ArcIMS\Jre\Lib\Ext are used to run the ArcIMS Administrator application. The original install of ArcIMS copies the entire Ext folder including all the .jar files to the Jre\Lib subfolder of the active Java Runtime Environment (JRE) or Java Development Kit (JDK). When an update is applied, these .jar files may or may not be updated. If they are not updated, the new version of ArcIMS will not match the version of the .jar files, and an error appears when ArcIMS Administrator is opened.
If the same error still exists when trying to run ArcIMS Administrator, rename or remove the Program Files\ArcGIS\ArcIMS\Jre\Lib\Ext folder and run a repair on ArcIMS from the Add/Remove Programs in the Control Panel. Once the repair is completed, repeat Steps 1-5.