So the short of it is that our program has Pepper Flash plugin embedded into Electron and everything works except we’re not able to utilize Flash’s print function. We also have no control over the source code of the .swf files.
We ran the Flash plugin outside of Electron and it creates a functional popup window just fine. Does anyone have any insight into how we can get this to work within Electron?
This won't work in Electron. It's a bug that's not fixed yet. Electron 12 drops Flash Plugin support.
The only workaround is to mimic everything related to printing in JS (which you your case might not be possible).