If you encounter an error like the image above, hopefully this article will be a solution.
Here are the steps:
2. Change post_max_size and upload_max_filesize to the desired size and click OK.
3. Try uploading the file again in WordPress.
Note: if the upload_max_filesize size is bigger than post_max_size, then WordPress will still follow the post_max_size size, in this case I changed both to 16MB.
You can see the upload file size limit by visiting the Media> Add New page, here are the before and after results.
Please try and good luck, thank you.