Does anyone know why I get this error every time I try to access the page where I have the saved data?
Show your relevant blocks, and confirm you are testing with iOS companion.
The operation (Procedure) Elements - you are passing an empty value to it.
Write something or not I keep getting the same error.
It would really help if you provided a screenshot of your relevant blocks, so we can see what you are trying to do, and where the problem may be.
To get an image of your blocks, right click in the Blocks Editor and select "Download Blocks as Image". You might want to use an image editor to crop etc. if required. Then post it here in the community.
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.
Use 'Do It' to see the value that is passed to the Procedure - it is not about writing anything.
Show us a screenshot from the initialize event of screen Diari2
And let us know, if you are using iOS...
Taifun
yes, i'm testing with iOS