I just upgraded from Mathematica 11.3 to Mathematica 12. Unfortunately, code that previously ran in a reasonable amount of time (say 10 sec or half a minute, does now not complete anymore before I abort it after 10 minutes or so.

This is a line of such code, which I cannot evaluate in Mathematica 12 anymore. The sum is just equal to 1, and Mathematica 11.3 computed this very quickly. What do I need to do to run this code in Mathematica 12? (I suspect I should use a different command or add assumptions of some sort?)

Thanks, Max

ass := {0 < w0, w0 <= 1, 0 < v0, v0 < 1, w0 <= v0, 0 < w1, w1/c1 <= 1,
   0 < v1, v1/c1 <= 1, 0 < c1, w1 <= v1, v1 <= c1, w1 <= c1, 
  v0 <= w1/c1};
pmf := ((g0 + b0e + b0l + g1 + b1)!/(g0!*b0e!*b0l!*g1!*b1!))*((
   v0 - w0)/(1 + c1))^g0*((w1/c1 - v0)/(1 + c1))^
  b0e*((1 - w1/c1)/(1 + c1))^b0l*((v1 - w1)/(1 + c1))^
  g1*((c1 - v1)/(1 + c1))^b1*((w0 + w1)/(1 + c1))^1;

FullSimplify[
 Sum[pmf, {g0, 0, \[Infinity]}, {b0e, 0, \[Infinity]}, {b0l, 
   0, \[Infinity]}, {g1, 0, \[Infinity]}, {b1, 0, \[Infinity]}, 
  Assumptions -> ass], Assumptions -> ass]