Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want.
Try this:
(1) look at each constraint and try to figure out which you don't expect;
(2) find the code that added the unwanted constraint or constraints and fix it. (
"<NSLayoutConstraint:0x7f844b716390 H:|-(30)-[UIButton:0x7f844b4be3c0'LOGIN'] (Names: '|':UIView:0x7f844b492a80 )>",
"<NSLayoutConstraint:0x7f844b706ee0 H:[UIButton:0x7f844b4be3c0'LOGIN'(100)]>",
"<NSLayoutConstraint:0x7f844b705dd0 H:[UIButton:0x7f844b4be3c0'LOGIN']-(80)-[UIButton:0x7f844b4c0520'SIGNUP']>",
"<NSLayoutConstraint:0x7f844b706f30 H:[UIButton:0x7f844b4c0520'SIGNUP'(100)]>",
"<NSLayoutConstraint:0x7f844b7147c0 H:[UIButton:0x7f844b4c0520'SIGNUP']-(30)-| (Names: '|':UIView:0x7f844b492a80 )>",
"<NSLayoutConstraint:0x7f844b519f70 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7f844b492a80(375)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7f844b705dd0 H:[UIButton:0x7f844b4be3c0'LOGIN']-(80)-[UIButton:0x7f844b4c0520'SIGNUP']>