Home → Techniques and Tips → All Products → Removing Outdated References to Project from the System Registry
Removing a version of Microsoft Project can sometimes leave behind "orphan" keys in the System Registry. These references to products that are no longer installed can prevent Palisade add-ins from working correctly with Project — you may see messages such as "Application-defined or object-defined error", "Automation error: Library not registered", "Error in loading DLL", "Could not contact the Microsoft Excel application", "File name or class name not found during Automation operation", or "Object variable or with block variable not set". Results graphs or other graphs may not appear as expected.
To search for and remove outdated COM Type Library registrations relating to Microsoft Project, please follow this procedure, which requires administrative rights:
Close Excel and Project.
Click » Start » Run, enter the command REGEDIT and click OK.
If the key does not exist, Microsoft Project may be able to re-create it. Close Registry Editor and open Project. There's no need to open an .MPP file. Close Project, then reopen Registry Editor and search for the key. If the key still does not exist, see Microsoft Project Installation below.
If the key does exist, click the + sign at the left to expand it. You will see one or more subkeys:
Identify the one(s) that do not match the version(s) of Microsoft Project you actually have installed. If all of them do match installed Project versions, omit steps 5 and 6.
You are about to delete the key(s) that correspond to versions of Microsoft Project you do not have. For safety's sake, you may want to back them up first. Right-click on {A7107640-94DF-1068-855E-00DD01075445}, select Export, and save the file where you'll be able to find it.
Right-click the 4.something key that does not belong, select Delete, and confirm the deletion. Repeat for each 4.something key that does not belong.
The {A7107640-94DF-1068-855E-00DD01075445} key can occur in more places. Usually they all have the same subkeys, but not always, so you need to examine each instance. Tap the F3 key to get to each of the others in turn. For each one, repeat steps 4 through 6 (click the + sign, export the key to a new file, and delete the orphaned 4.something entries).
Close Registry Editor.
Launch @RISK, and you should now be able to import .MPP files. After verifying @RISK, and running Project independently of @RISK, you can delete the saved .REG file.
Microsoft Project Installation
If the {A7107640-94DF-1068-855E-00DD01075445} key does not exist, and Microsoft Project did not re-create it, you may have a problem with your installation of Project.
In Project, make sure you have the latest service pack installed. If not, download it and install it.
In Control Panel » Programs and Features (or Add or Remove Programs), do a Repair of Microsoft Project. (If Project, Microsoft Project, or Microsoft Office Project does not appear on a separate line, it is part of the Microsoft Office line and you should repair that.)
If all else fails, uninstall and reinstall Project, or uninstall and reinstall Office if Project is part of the Office install. (We had one customer with this issue, and none of the above worked for him, but the uninstall and reinstall solved the problem.)
Excel's COM Registrations
If the above don't solve the problem, the culprit could be Excel's COM registrations rather than Project's. Please see Removing Outdated References to Office from the System Registry to check for incorrect Excel COM registrations and remove them. The procedure is similar to the procedure in the first section of this article, but the keys are different.
Last edited: 2016-04-01