Excel crashing without error when form.Controls.Add is called

Hello and thank you for reaching out!

I understand that you're experiencing an issue with Excel crashing without any error message when using the form.Controls.Add method in VBA. I've done some research and compiled some insights that might be helpful in resolving this problem. Please allow me to elaborate:

Potential Causes and Solutions:

1. Control Reference: Ensure that the control you're trying to add using form.Controls.Add exists in the project's toolbox. If it's not present, add it before attempting to create an instance.
2. Object Type Mismatch: Verify that the type of control you're adding matches the type specified in the form.Controls.Add method. For example, if you're adding a MSForms.TextBox control, ensure that you use the correct class name.
3. Control Name: Make sure that the name you assign to the control (the second argument in form.Controls.Add) is unique within the form. Duplicate control names can lead to conflicts.
4. Design Mode: If you're adding controls during design time (when the form is open in design mode), ensure that you're not trying to add controls to a protected worksheet or a locked form. These restrictions can prevent changes to the form's structure.
5. Event Handlers: Be cautious when assigning event handlers to controls added dynamically. If you're adding event handlers in code, make sure that the event procedures exist and are properly defined.
6. Object Variables: When working with controls added dynamically, it's important to properly declare and assign object variables to those controls. This ensures that you can access and manipulate them later in your code.
7. Form Initialization: Sometimes, adding controls dynamically during form initialization (in the UserForm_Initialize event) can cause issues. Try adding the controls after the form has fully loaded.
8. Form Resizing: If you're dynamically adding controls that affect the form's size or position, make sure to handle the UserForm_Resize event to adjust the controls' positions accordingly.

If you've checked these potential causes and the issue persists, it might be beneficial to share more specific details about your code and the steps leading up to the crash. You can provide this information in your reply, and I'll do my best to assist you further. Remember to test your code thoroughly after making changes and ensure that you're using the latest version of Excel. If you continue to experience the issue, you might want to consider posting your question on a relevant forum or platform where other Excel users and experts can provide additional insights and suggestions.