key error = "Operation-Location"

I modified the code to accept local images using: https://stackoverflow.com/questions/63907566/using-local-image-for-read-3-0-azure-cognitive-service-computer-vision

I modified to iterate over the code to detect text in multiple local images (around 100 images); however, I get key error = "Operation-Location" after a few number of iterations (5-8) varying every rerun. How do I go about fixing it?