It sounds like either the player you're viewing the produced clip on isn't displaying it correctly or else you may have produced to a different profile than usual.

For the first case, try playing the clip in a different media player. For the second case, 480 is a very low resolution and you might want to try using the Profile Analyzer to suggest more appropriate settings based on the actual clips in your project.

Quote Hi,

I'm rendering a video I have just edited. My problem is that the ratio of the video changes after it is produced. When I'm Powerdirector the ratio is 16:9, which is how I've always produced videos, but the one I'm currently changes to 4:3 instead.

My rendering format is HEVC and for testing my video, I usually produce on the lowest setting of 480.

Yes, the 4:3 display is correct, assuming you are using like the HEVC MP4 640x480/30p produce profile for testing your video as stated. To test, you may try 1280x720/30p which is a larger file but will display your 16:9 correctly for testing.

Jeff