"Create your school first to open this section."
Where: any school screen, opened before the school was created (for example an old link or a bookmark).
Why: the account has no school yet: no school data is reachable until step 1 of setup is done.
What to do: open the app: it leads to setup. Fill in step 1 (school name and styles taught), then continue. Everything can be changed later.
Didn't find your answer?
Write to bonjour@martialnote.com from your account's address, saying which screen is involved and the message shown. Support is by email only, with no guaranteed response time. Never send information about your students.