There is something wrong with this forum software, because I’m sure I used the add image button to upload the original schematic. I didn’t use any external hosting.
I can’t edit the OP to fix it, but this is the schematic that was posted there:
No problem! Thanks a ton @tobia 
I think this happened when the community.spark.io URL got deprecated and some of the uploaded images weren't migrated.
I have copied your schematic into the opening post.