When adding a field and having an error, all fields get blank

[Kai]

User is clicking on "Fields", add field, then inserts the data, and submits the data. 

As soon as there is an error, the site is shown again and all fields are reset / blank. 

Then of course, the user has to insert all data again - which I did so many times of the first day of developing with processwire. 

Please be so kind and fix this.