What browser are you using, and what browser version?
Viewing post in Tiny RPG Studio for Sega Master System comments
I made a quick test map for it, here it is
https://andredarcie.github.io/tiny-rpg-studio/#vy.oyXQAB_4CAgYACAgICAgICAgICAgIC...
I was trying to import it from the exported .html file, but no luck
This link seems to save and load more reliably than the itch.io one, but it still seems unable to load the external project, for some reason.:
https://haroldo-ok.github.io/tiny-rpg-studio-sms/sms-rpg-studio.html
Okay the new version implement "Import" and "Export" buttons, and if the site blocks the "Save" button, it will display a popup where you can copy the URL.
https://haroldo-ok.itch.io/tiny-rpg-studio-sms/devlog/1571031/v0120-implement-im...
BTW: even after those fixes, your specific link (https://andredarcie.github.io/tiny-rpg-studio/#vy.oyXQAB_4CAgYACAgICAgICAgICAgIC...) seems to be failing on the importer; I'll take a look at this specific bug later on.