I'm developing a VBA program that uses several UserForms.

As the program gets more complicated (and more UserForms are added), Excel
has started freezing/crashing on me - despite the fact that the file is small
(428 KB).

Is the freezing/crashing due to the number of UserForms (11 or 12)?

Could I avoid this problem by combining two UserForms into one and
displaying the controls associated with the two forms one at a time,
depending on which option is selected in the Main Form?

Any advice would be greatly appreciated.

Thanks