From what you write, it seems as if only some people get the error, or only some of the time? Can you clarify?
Do you know what Lectora Action is running (if any) when you receive the error? If it isn’t an explicit Action, what precedes the error? Page navigation? Completing a test? Just sitting idle on the same page?
What LMS are you using? Have you tested the course in another, say a free SCORM Cloud account?