Error: Error using VideoReader/init Failed to initialize internal resources.

I am trying to save a part of a video from an online IP cam as an avi format. When trying to read the avi file an error pops up:

Error using VideoReader
Failed to initialize internal resources.

I tried to change the format of the written video several times with no luck.

here is the code for writing and reading the video:

% Read video
cam = ipcam('http://138.188.39.235:88/mjpg/video.mjpg', '', '', 'Timeout', 200);
vidWriter = VideoWriter('frames.mp4');

open(vidWriter);
for index = 1:0.25:50
   % Acquire a single frame.
   Image = snapshot(cam);

   % Write frame to video.
   writeVideo(vidWriter, Image);

end
   clear cam
   
obj = VideoReader('frames.mp4');