This is a problem with sourceforge servers sending wrong HTTP headers. You can read this thread in the developers for a temporary workaround:
https://lists.launchpad.net/schooltool-developers/msg00346.html
This is a problem with sourceforge servers sending wrong HTTP headers. You can read this thread in the developers for a temporary workaround:
https:/ /lists. launchpad. net/schooltool- developers/ msg00346. html