After installing Service Pack 2 for ArcGIS Desktop 9.3.1, opening a map document from Windows Explorer, ArcCatalog, Windows Desktop, Windows Recent Documents, or the Web does not open it in a new ArcMap session. That is, if you open an existing map document, ArcMap opens as expected. However, if you now open another map document, it will not start a new instance of ArcMap. Instead, the map document is sent to the existing instance.
This is a known issue. For updates on the status, you can use bug number NIM059009. Esri is working on a permanent solution to this issue. In the meantime, please use the following workaround:
- Run C:Program FilesCommon FilesArcGISbinArcGISFileHandler.exe.
- Click OK to close the ArcGIS File Handler application.
Map documents should now open correctly.
Esri apologizes for any inconveniece this may have caused you.
- Jeff M., Desktop Development Lead – User Advocacy Group, Esri Support Services
Note that if you have installed the latest version of ArcGIS Explorer (build 1500 – http://www.esri.com/software/arcgis/explorer/index.html), you will not see this issue. ArcGIS Explorer installed a new version of ArcGISFileHandler.exe.