The problem is that your Render Resolution Y = 399. You didn't mention your render settings but I assume that your output format is: FFMPEG Video with an H.264 codec. The way this encoder works is by dividing your image into macroblocks of a fixed size (e.g. 4x4) and compress these blocks in parallel. Therefore your width and height must be divisible by 2. If you should change your Height to 400, I think the problem will be fixed.
If you need this 1500 x 399 resolution, you can render it out as a PNG sequence. Then, you can use FFMPEG to create a movie (e.g. MP4) of it. There are plenty of solutions on the internet to do this; see for example https://stackoverflow.com/questions/60788967/ffmpeg-width-not-divisible-by-2-375x500-error.
You will find a more elaborate answer for this common question on https://vse-docs.readthedocs.io/render/postprocessing/ffmpeg/ffmpeg.html