1. Design As An AfterthoughtRather than designing their course to be easy to use, in a logical, sequential manner, course designers (or academics who think they are courses designers), just load up a mishmash of stuff and blame the LMS when the students can't make sense of it. When designing a course you have to carefully curate and sequence the experience.
2. Expectations Of Social InteractivitySocial learning is something which has to be designed into a course and students have to be trained how to work together, be it online or in a classroom. Social learning is not something you can delegate to the LMS to do for you.
Even under the best conditions, learning is a hard, mostly solitary, frustrating experience. Giving students the expectation it will be easy, fun and social, is doing them a disservice and may be dangerous to their mental wellbeing.
3. Expectations of a Fun User ExperienceLearning is not fun, it is hard work. Courses which have a false send of jollity are intensely frustrating for the student.
4. Expectations Of AccessibilityThe best LMS can't make up for a lack of accessibility of educational content. Most LMS will now reflow content for mobile devices. But course designers need to ensure their content fits on devices and networks students use.
5. Inadequate or Excessive Use of Tracking And Reporting FeaturesMost LMS now have features to allow students to track how they are doing. However, learning designers needs to switch on these features. Also this doesn't remove responsibility from the instructor to keeping track of how their students are doing and provide feedback.
Some instructors go to the other extreme and closely monitor how and when the students use the LMS. Use, or lack of use, of the LMS should not be used as a proxy form of assessment.