Help : Missing firmware copter-3.4.3 on MP 1.3.44

Hi all,

Please help,
I upgraded to latest MP 1.3.44 and would like to downgrade copter-3.4.5 to copter-3.4.3, in “pick previous firmware” not showing copter-3.4.3.

What happened with my MP?

Reason to downgrade:
Copter couldn’t armed
Quad 210mm, FC pixfalcon, Dys Blheli, 2300kv

Any help wil be appreciated