The form required to view this message cannot be displayed
I get an error message when trying to add an appointment to my calendar:
"The form required to view this message cannot be displayed. Contact your administrator."
What can I do to repair this?
This usually happens when you are using a custom form within that folder and the form cache has become corrupted or the add-in that was using that form is no longer installed on your system.
A “form” is basically the design and the function of the fields when you open or create a new Outlook items such as a message, appointment or contact.
Clearing the forms cache
The first thing you should try is clearing the forms cache. This will make sure that, in the case of using a custom form, the latest published version of your custom forms gets loaded again. In the case that you just uninstalled an application that was using a custom form, it will purge this cached form and Outlook will try to load the original message form.
To clear the cache;
- File-> Options-> Advanced-> section: Developers-> button Custom Forms…-> button Manage Forms…-> button Clear Cache
When you want to clear it manually, delete all contents from the following directory when Outlook is close;
C:\Users\%username%\AppData\Local\Microsoft\FORMS
Verify that Outlook is configured to use the correct form
If you still have this issue after clearing the forms cache, make sure that Outlook is configured to open the correct form when creating a new item in that folder.
To see which form is set as the default, right click on the folder and choose Properties. Here you’ll find a drop down list called; When posting to this folder, use:.
You can find the default for each folder in the list below;
| Folder containing | Default form |
|---|---|
| email messages | IPM.Post |
| contact items | IPM.Contact |
| calendar items | IPM.Appointment |
| task items | IPM.Task |
| notes | IPM.StickyNote |
| journal items | IPM.Activity |
Live Local add-in
A common cause for appointment forms to get corrupted is if you have or previously had the Live Search Maps Add-In for Outlook installed.
To see if you still have calendar items based on this add-in in your Calendar folder, switch your view to “All Appointments” via the View menu. Icons that were based on this add-in will expose the following icon; 
If you see this icon, you’ll find detailed instructions on how to properly remove remnants of the Live Search Maps Add-in here (archived).
