YGOPro is developed by Argon.Sun/Flourohydride. YGOPro Percy is a version that is modded in many ways to make it better. DevPro is a Mod of Percy given to a group that develops a Launcher for start much like the first flavor, it is distrubed with DevPro software which connects to a different type of server. YGOPro Percy has an intergrated launcher while DevPro has an external server. They aren't competitors, just divergences.

Both are of good quality but the layout is different. I would say its just personal preference. Some are good using that while others are feeling more comfortable with the other.

NOTE: For Manual Mode press and hold A on your keyboard. To Hide Gorz, Tragoedia, Maxx C, Fader etc. press S.

How We Fix The Side Deck Crash Bug in DevPro?

Very simple we enter "options" then search for "Enable Directx" and take out the V on it.
like the Pictures Here!