3.2 on Windows Phone 8 just shows black screen

You’re welcome.
Glad that worked for you.

for me, reinstall monogame using package manager console:
PM> Install-Package MonoGame
solve the problem

That worked perfectly for me, fixed the same problem as OP.

Thankyou thankyou thankyou thankyou.

This thread has just about saved me from topping myself.

I know it’s all I ever go on about but it would be great to get another official release of MonoGame out to address this issue. Any chance, @TomSpilman?