Managed to do incremental upgrade from Moodle 1.9.4 to moodle 3.0, There are 60 courses with a lesson each, and now none of the lessons work
Debugging shows error as shown below
Just for information, upgrade from 1.9.19 to 2.0 wasnt happening for some tables are with character set Latin, and some with UniCode, so had to manually change character set to unicode together with database from MyISAM to InnoDB, after that upgrades had been seamless apart from Lessons dont work.