Reason: 

    Fix:

Step 1: ../wp-content/themes/exizt/functions.php

add_image_size(‘nouexist_198x254’, 204, 262, true);
change
add_image_size(‘nouexist_198x254’, 212, 272, true);

Step 2:  Then delete the original image in the Media Library and re-upload the image

Result: