Micro converter SDI to HDMI problem

I am trying to display information on a raspberry Pi 3 on an ATEM using BMD HDMI to SDI micro converter.
I am not getting any pictures out when I connect Raspberry Pi 3 to BMD micro converter.
I can get the raspberry's pictures when connected directly to a TV, and can get SDI out when the converter is fed from my Mac book or sky box.
Any suggestion is welcomed

Which Atem, and what project setting ?

You'll need to match the Pi's hdmi output to the Atem
by editing the raspi-config.txt file in the Pi's root folder.

[Gary Adams]

Also make sure the Raspberry Pi doesn't output 60 Hz as that won't work on the SDI inputs of most ATEMS.

Regards, Gary

Also make sure the Raspberry Pi doesn't output 60 Hz as that won't work on the SDI inputs of most ATEMS.

Regards, Gary

Sorry for this very late reply Gary.
I know it's been a while for this post but the benefit of other members who might encounter the similar problem, all I did was go into config and add the following

hdmi_group=1
hdmi_mode=31

These line are for 1080p50 output.

I also had to comment out the default line, I can't remember exactly what it was.