I suspect Blogger is using CDN (Content Deilvery Network). You can no longer download or resize images.
Fret not, I am here to share with you how to resize your image. I am still investigating how to download the image.
You can on longer change the URL path to s0, s640, s800, s1024 to resize. Instead, you can append =s0, =s640, =s800, =s1024 (even odd size like =s1200) at the end of the URL to resize your images.
E.g.
Original size
https://blogger.googleusercontent.com/img/a/AVvXsEhrmeaxCmz6khcfpleyqv5C_sti5OtZug7hLe6nzupcRMXyv6sJJA9c5B_LS6D0lRpao9rqWnKxerAf4SHTnRHFrBwCY-JkpE_vih-xFslb_QKHbEqdYVxXLvOZE5IxDnhyJIcc4tUWF57CmfzaCk0y-NySl7JGzHG9W3iTiwaDfYYPBjCA-2wv0-je=s0
Resized
https://blogger.googleusercontent.com/img/a/AVvXsEhrmeaxCmz6khcfpleyqv5C_sti5OtZug7hLe6nzupcRMXyv6sJJA9c5B_LS6D0lRpao9rqWnKxerAf4SHTnRHFrBwCY-JkpE_vih-xFslb_QKHbEqdYVxXLvOZE5IxDnhyJIcc4tUWF57CmfzaCk0y-NySl7JGzHG9W3iTiwaDfYYPBjCA-2wv0-je=s1200
Good thing though Blogger can display the original image in it's full glory.