Is this a Unity error ?
Aah, picture doesn`t work. Here is the link: https://picload.org/image/roporgar/textfield_error.jpg
Sometimes it shows cryptic numbers and sometimes readable text. I have this problem with different assets from the store. I am using Unity 5.5.1p3.
That window is no build in, it comes from a asset that you have imported into your project.
It looks like something went wrong with it ( is has a bug ) or its not compatible with the current unity version.
If this asset should be compatible with unity 5.5 contact the author about this problem.
