I cant able to create a new doctype "Postal Code"

Hi All,
I need to create New doctype named “Postal Code” under any module but i cant able to create please guide me how to create “Postal code” doctype under “Service” module

if i able to create this error is coming

but in “Service” module is already having

Thanks in Advance

Did you migrate the site? And the build app (bench build --force)?

This is the latest IP which were using for last couple of weeks