When a field with text data such as URL containing an underscore, when I press edit all textboxes are blank.
Please fill bug reports for bugs.
I would need more information to reproduce this one (example of table structure and data). In my case, if a field contains underscore then everything works as expected.
It seems that if both a period (.) and underscore (_) appear in the same field, you get the blank page ( error "No rows."). Bug report submitted.