Question: What does this error mean in pdsolve?

eq1 := f(r)*((diff(g(t, phi, r), t))*a^2+(diff(g(t, phi, r), t))*r^2+a*(diff(g(t, phi, r), phi)))/(sqrt(-g(t, phi, r)^2*f(r)^2+1)*sqrt(-(r^2+a^2*cos(theta)^2)*(2*M*r-a^2-r^2)))

f(r)*((diff(g(t, phi, r), t))*a^2+(diff(g(t, phi, r), t))*r^2+a*(diff(g(t, phi, r), phi)))/((-g(t, phi, r)^2*f(r)^2+1)^(1/2)*(-(r^2+a^2*cos(theta)^2)*(2*M*r-a^2-r^2))^(1/2))

(1)

eq2 := (((-a*cos(theta)^2+a)*f(r)^2*g(t, phi, r)^2+a*cos(theta)^2-a)*(diff(g(t, phi, r), phi, t))+(g(t, phi, r)^2*f(r)^2-1)*(diff(g(t, phi, r), phi, phi))+(-(diff(g(t, phi, r), phi))+(diff(g(t, phi, r), t))*a*(cos(theta)-1)*(cos(theta)+1))*(diff(g(t, phi, r), phi))*f(r)^2*g(t, phi, r))*f(r)/((-g(t, phi, r)^2*f(r)^2+1)^(3/2)*sin(theta))

(((-a*cos(theta)^2+a)*f(r)^2*g(t, phi, r)^2+a*cos(theta)^2-a)*(diff(diff(g(t, phi, r), phi), t))+(g(t, phi, r)^2*f(r)^2-1)*(diff(diff(g(t, phi, r), phi), phi))+(-(diff(g(t, phi, r), phi))+(diff(g(t, phi, r), t))*a*(cos(theta)-1)*(cos(theta)+1))*(diff(g(t, phi, r), phi))*f(r)^2*g(t, phi, r))*f(r)/((-g(t, phi, r)^2*f(r)^2+1)^(3/2)*sin(theta))

(2)

pdsolve([eq1, eq2])

Error, (in pdsolve/sys) found the element '_F4' repeated in the indication of blocks variables

 

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Download problemfile.mw

I am trying to solve these two coupled PDE and am getting this error. Does anyone know what this mean?

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