There are several conditions and practices which may ruin a course completely. The following list is a collection of such conditions and practices extracted from http://cloudworks.ac.uk/cloud/view/2597. Extending the list is certainly possible, which is why it should not be regarded as complete but as an initiator for reflection of one’s own course development.
Lack of structure
Lack of adherence to clear (and explicit/written) aims
Teachers set unrealistic learning outcomes
Poor delivery, e.g. non-timed u-link docs, boring didactic lectures
Poor support for practice
Lack of resources
Assessment does not meet course objectives
Poor pitch of teaching content for student group
Neglecting subjugated learning
Teachers fail to adapt to the student group
Not involving students as active learners
Teachers fail to incorporate students’ feedback
Difficulties with access to necessary material
Not considering the students’ pre-knowledge
No/ very little interaction with the students
…