I had the same issue and I tried all of the suggestions mentioned in WordPress forums, to no avail. What worked for me is changing the memory upload limit. To do this, you just need to create a document titled “php.ini” in the root directory of your website. Within that document, the following criteria needs to be listed:
memory_limit = 512M;
upload_max_filesize = 512M;
post_max_size = 512M
(you can specify what you want the upload MB limit to be – doesn’t have to be 512).