Ok, sorry, my fault.

Just checked the log in SmartThings and there was an error saying that it couldn't find a device type.

I went and double check your instructions (which I should have done first) and realized that it seems like I went too fast when configuring the smartapp and I skipped the device handler.

Just added the device handler and now things work as they should!

Actually, I can save it if I don't select any trigger. After that, if I try to modify the app and select a trigger, I am getting a "Error saving page" message.

Also, I didn't add/delete/change any of my trigger after installing the smart app inside SmartThings.

I just added the smart app to my SmartThings. I can see it from the mobile app but when I try to save it (after selecting my triggers), I always get a message saying "An unexpected error occurred".

Any idea what might be causing this?

Ok, good to know! Thank you!

I registered this afternoon, installed the agent on a Debian and it works. I didn't have any options on the web interface, only the 4 original triggers. They work but I can't edit them. Discovered that there is a subscription, guessed it was needed to activate some functions. Went and paid the 12$, which is a quite ok price. Some hours later, still can't edit anything. Am i missing something?