Can't Use Custom Contact form in Outlook Classic since early January 2026

[COMike]

Operating system::    Win 11
Outlook version:     classic Outlook
Email type or host:    Exchange

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Since early this year, not sure of exact date, I have not been able to use my custom built contact form in Outlook Classic. The form has worked without any flaws since 2023, the last redesign, but has been in use in mostly the same form for 10+ years. When I try to use, I get the error below. I get this error when I try to open a contact, create a new contact, edit a contact, or even try to use the developer tools to design a new form by opening the default Outlook contact form. Called an IT tech support person and he ran through the obvious and no luck fixing.

I saw Diane's registry edit to allow VBScript in a custom form, pic below, and thought maybe that would help but when I navigated to that registry location, My system does not have a "Forms" section under Outlook.

Googling the issue, seems others are having similar, but not exactly the same, issues related to a Microsoft security update.

Thanks for any thoughts anyone has.

 

[Hornblower409]

My system does not have a "Forms" section under Outlook.

You have to add the keys.
Custom form script is now disabled by default - Microsoft Support

 

[Hornblower409]

or even try to use the developer tools to design a new form by opening the default Outlook contact form.

That doesn't fit the pattern for a TrustedFormScriptList problem.

If you are doing this. It should not throw any errors.

Developer -> Design a Form
Look in: Standard Forms Library
Select "Contact"
[Open]

 

[Hornblower409]

Since early this year, not sure of exact date, I have not been able to use my custom built contact form in Outlook Classic.

HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Security
DWORD DisableAllActiveX = 0

 

[COMike]

That doesn't fit the pattern for a TrustedFormScriptList problem.

If you are doing this. It should not throw any errors.

Developer -> Design a Form
Look in: Standard Forms Library
Select "Contact"
[Open]

Hornblower409, when I open the standard "Contact" form in Design a Form, I get the error message and then the form opens with certain fields missing, like the "email display" and the "Notes" fields. Any further thoughts what I have going on?

 

[Hornblower409]

I open the standard "Contact" form in Design a Form, I get the error message and then the form opens with certain fields missing

I was able to duplicate. The fix is:

HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Security
DWORD DisableAllActiveX = 0

 

[COMike]

I was able to duplicate. The fix is:

HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Security
DWORD DisableAllActiveX = 0

The fix worked! Thanks so much.

Now that I have made those changes, how big a security hole have I re-opened in my system?

 

[Hornblower409]

Now that I have made those changes, how big a security hole have I re-opened in my system?

I'm not qualified to answer that.
ActiveX controls are disabled by default in Microsoft 365 and Office 2024 - Microsoft Support

Found a better way. Using Word/Excel (which do have ActiveX Settings).

Word -> File -> Options -> Trust Center -> [Trust Center Settings] -> ActiveX Settings

This sets the Registry as:

HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Security
DisableAllActiveX = 0
UFIControls = 4