flawed

having a mistake or weakness in its basic structure or principles

having important and significant mistakes or weaknesses

having very significant mistakes or weaknesses

having a mistake or weakness as a natural and permanent part

having fundamental and serious mistakes or weaknesses

having a mistake or weakness so serious that it causes failure

having a large number or degree of mistakes or weaknesses

having minor mistakes or weaknesses

having mistakes or weaknesses to some degree

so flawed that there is no hope of correction or success

having a mistake or weakness in the methods used

having a mistake or weakness in its underlying concept or idea

to have a mistake or weakness

to appear to have a mistake or weakness

to continue to have a mistake or weakness