Issue in Release v12.0.4

I have created a chaild tables in project and tasks doctype, now when I open any records have any data in child tables show me this ERROR
ImportError: Module import failed for Lessons (erpnext.projects.doctype.lessons.lessons Error: No module named lessons.lessons)

in this case, my child table named lessons

It seems to duplicate the child table name

Any help here?

Solved after make updates in child tables.