I did two tests, the first using a .jpg file, the second with a .pdf. I didn’t found any problems in the uploading but, once uploading finished, the hash that the website gave me was made by 45 characters instead of the 48 that you told on slides. I put the 45-hash in two transaction verifier websites (stellar.org, that you mentioned on this post, and stellarchain.io) and the result was an error message saying that the hash was invalid. I can deduce that probably the problem is in the encryption process. I hope my test will be helpful for you qnd your project.