I have a FLIR A3xx camera but I cannot see the image stream. What is wrong?

This issue can be related to the fact that your are using old filters.

Copy these files :

C:\Program Files\FLIR System\FLIR Device Drivers\fsrtsp_MT.ax
C:\Program Files\FLIR System\FLIR Device Drivers\flirdxfilter_MT.ax

and replace the files below:

C:\Program Files\FLIR System\Shared\fsrtsp_MT.ax
C:\Program Files\FLIR System\Shared\flirdxfilter_MT.ax

Now you should be able to see the image stream.