Cannot save presentation without removing digital signatures

[redhorse]

I have a presentation with VBA code that I created on my home computer along
with the necessary "self certification" necessary to allow it to run the next
time I open it.

I have since copied this presentation to my work laptop, and following the
same steps I used at home, I was able to get it to run the VBA code.
However, when I try to save the presentation, I get the message, "This
presentation contains digital signatures. Saving the presentation removes
all existing signatures."

Then, true to its word, if I continue with the save, the digital signatures
are removed. If I reopen the presentation, I need to add the digital
signatures back in before the VBA code will run.

How can I get the presentation to save without removing digital signatures?

 

[redhorse]

Just as an addendum, I have a second presentation with similar VBA code that
I was able to transfer to my laptop and had it working fine. So the problem
seems to be specific to the other file.