Having Maple 12 I try to use concurrent gfun version 3.52 and have problems
to run an example (from a lecture):

libname:= "D:\\_Work\\Maple_Work\\z_Packages\\gfun", libname; # my setting

with(gfun) : gfun:-version();
with(NumGfun) :
                                 3.52

# example

alpha, beta, Gamma, delta := 1, 1/3, 1/2, 3 ;

# motivation to use the package
evalf(HeunD(alpha, beta, Gamma, delta, -0.99)) ;

  Warning, breaking after 2000 terms, the series is not converging
                              undefined

# attack
deq[Heun] := { diff(y(z), z, z)-
 (-2*z^5+4*z^3+z^4*alpha-2*z-alpha)*(diff(y(z), z))/((z-1)^3*(z+1)^3)-
 (-z^2*beta+(-Gamma-2*alpha)*z-delta)*y(z)/((z-1)^3*(z+1)^3), 
 y(0)=1, D(y)(0)=0 } ;

# now start using the package
myHeunD := diffeqtoproc(deq[Heun], y(z)) ;

  Error, (in gfun:-NumGfun:-diffeqtoproc:-trial_run) 
  FromCoefficientList is not a command in the PolynomialTools package


Question: is that a problem with incompatible versions and if so which
is the correct gfun to be used with Maple 12?