Adobe must officially support Windows 10 before you can really expect things to work well. There are several users in multiple forums reporting issues. Such as in Flash the color panel (selecting colors) appears to break quite often and crash Flash.
Until Adobe officially supports Windows 10 I would not expect to use it.
For what it's worth, I have installed Windows 10 and use Flash CS6 just fine so maybe download that and use it until they all get on the same page? I seem to remember having no problem with Flash 2015 as well but I'll check to make sure. I would suggest that it might actually be the Wacom drivers themselves like the Feel it driver instead. I don't think Wacom officially supports Windows 10 yet either.
I had the same issue and almost give up on flash. But I solved this buy uninstalling all Wacom drivers from cintiq companion and installed an old version of the drive. Now my flash is working perfect!
Sorry for my bad English and hope this works for you!
Can you try by installing an older version of Wacom Drivers (6.3.11).
I have sent you a PM, please check.
Appreciate your early response.