Error: New Schema Invalid Type for Block # (I looked on forums)

[KarakoDarren]

• Error: New schema is incompatible with the current setting value. Invalid value for type in block '1524770014057'. Type must be defined in schema..New schema is incompatible with the current setting value. Invalid value for type in block '1524770292306'. Type must be defined in schema..New schema is incompatible with the current setting value. Invalid value for type in block '1524770296206'. Type must be defined in schema.

Hi I'm getting this error when trying to save my header.liquid. 

How do I even locate block "1524770296206" to define or delete?

I read a bunch of forum posts to no avail. I've controlled+f to look for block "1524770296206" and header but also to no avail.

Any help would be greatly appreciated. Thank you!