Yeah, I've updated now as well to the creators update and my Kixforms.net scripts work fine.
The Classic KixForms scripts are unreliable, some work and some crash.
Unfortunately it isn't updated anymore 2.47 was the last version and the author isn't around much :-/

 Code:
The description for Event ID 5 from source KIXTART cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

If the event originated on another computer, the display information had to be saved with the event.

The following information was included with the event: 

Fatal exception occurred.
 Error : (0xc0000005/-1073741819)


The GUI does appear sometimes, so it's hard to figure out when it exactly crashes.
I'll have to build a kixforms script from scratch to see where it crashes.