Please check the list of installed add-ins in File -> Options -> Add-ins.
Typically the following Excel add-ins will be active:
- Analysis Toolpak
- and/or Microsoft Power ...
Depending on load order somehow the Analysis Toolpak or Microsoft Power (Map/View/Pivot) de-activates the loading of other Excel Add-ins. COM Excel Add-ins are not hindered.
The solution is to change the load order:
- Deactivate in Excel add-ins the Analysis Toolpak and Analysis Toolpak - VBA.
- Deactivate in COM add-ins the Microsoft Power Map, Microsoft Power Pivot and Microsoft Power View.
- Restart Excel.
- Answer "Yes" on the question.
- Activate again in Excel add-ins the Analysis Toolpak and Analysis Toolpak - VBA.
- Activate again in COM add-ins the Microsoft Power Map, Microsoft Power Pivot and Microsoft Power View.
- Restart Excel.
Loading of all add-ins is then fixed. The actual reason why Excel or the other add-ins disable the XLAM is unknown.