Hi, I am getting a deletion error when I am trying to change a form on a Sales Order record, both via UI and Server side script. Does anyone know what is causing this?

You cannot delete this transaction because there are other transactions linked to this one.

you have related records on this SO. you need to find them and delete them first, then you can delete SO

I am not trying to delete SO, I am changing the form

is the period closed? are there any forms tied to this form?

Nope

any scripts on SO that prevent it?

In my experience, email and print templates are stored with the transaction form used to create that transaction, so it has ties to the that form. In the Custom Transaction Form page for that form, It is strange that editing the form produces an error message that mentioned deleting dependent records. I'd look for the "Linked Forms" subtab to look for other transaction types that are explicitly linked to that form. That might give you a lead of where to look.

Thats a great point, thank you!

@KnotKnick - didn’t you just say there were no linked forms???