When the LMS is setup with a reverse proxy which consumes a bunch of the initial characters in the URL/path not using the ASCII short name will cause this error when the package is loaded. When I publish for SCORM I select the Short ASCII name feature so the course if loaded deep on a server will not lose the page relationships to one another.
On occasion the publish wonks and let’s one or two long named files into the .zip package. I delete all of the published files in the SCORM/HTML folder, double check I have the short ASCII checkbox enabled, and repackage. I double check the files in the package don’t have any A001_really long name reference, and then load to LMS. Usually fixes the problem.
I have also had it occur at the end if I used the wrong case or complete value. I have to remember our LMS is completed, and incomplete all lowercase no deviations.