Some difficulties, whether technical or pedagogical and involving both teachers and students, will always arise in the context of a distance course.
These might be technical problems (Internet connection, configuring peripherals, etc.) or pedagogical problems (activities that are too lengthy, exercises that are too complex to be done online, etc.).
In a classroom-presented course, the experienced teacher will know how to deal with problems by making some spontaneous changes in the lesson of the day so as to be able to continue the course without too much difficulty.
Still, it might be more complicated to improvise online. It thus becomes necessary to plan for substitute activities and supplementary modes of communication in case of unexpected events.
Learners enrolled in distance courses must nevertheless expect some setbacks. These are part of the game, provided that such events do not interfere significantly with the delivery of the course.
It is thus important to maintain proper communication with each of the students throughout the course so as to ensure that difficulties related to distance do not take precedence over learning.