I tested this with the latest versions of Isadora and OBS and it works OK for me with AMD Radeon R9 200.
First of all, does the Isadora output work with other software such as Resolume or Magic Music Visuals ? These have demonstration version to find out.
If you are using the Spout2 capture plugin for OBS, RH click on it and Properties. For “Spout senders” drop down the list and select “Isadora: Stage 1”.
If that doesn’t work, it’s a clue we can follow. So try something else.
Download the Spout2 repository. You will get “Spout2-2.007.zip”. Unzip it somewhere and navigate to :
SPOUTSDK > SpoutDirectX > SpoutDX > Binaries > Examples.
There you will find “Tutorial07.exe” which is a receiver. Open it to find whether you receive from the Isadora plugin.
Finally, in SpoutSettings, click “Diagnostics > Copy” and paste the results here.