Error: Setting 'type_header_base_size' must be a valid number

[tingprint]

Hi.!

I'm trying to copy the entire code from settings_data.json file from one theme to the updated theme, but there is an error after I'm trying to save the code in the updated theme. Error: Setting 'type_header_base_size' must be a valid number. 

What does it mean and how to solve this?

Thanks in advance!