By reading my previous message i realize it kinda sounded like i was selling out chrome. And that's not what i intended. Firefox is great. Chrome is just my own preferred browser and it is intact by statistic the most popular. That's why i asked why you didn't just use Chrome if it fixed the problem.
Well you must have seen this! The solution is only the browser Mozilla Firefox because NPAPI plugins/flags will stop after Chrome version 45. I don't say it doesn't work it does but on some machines Flash player works best on Firefox
Mozilla is also dropping NPAPI support on FireFox sometime next year. Like Google did earlier this year.
And that's actually a good thing. Improving both browsers by dropping old habits.
NPAPI brings unnecessary code that have to be processed to the browser and it slows it down. It can also be a security concern.
I have never heard about flash player on some machines
working better using FireFox. It's not true.
I could believe that FireFox itself takes better advantage of Flash, but not that it has to be a specific machine in order to do so.
Still doesn't matter because if an old HTC desire can run flash, it's not setting the requirements very high. Not to mention that HTML5 is replacing it. So flash support is also gonna be dropped one day.
Anyway, this is getting off topic. I'll let someone else solve your problem on MS Edge.