Importing the Italian mwb does not return the Congregation Bible Study to TB. The difficult way to do this is to first delete and then add the week's programme from scratch into Settings - LMM Meeting - Schedule tab. (the + sign to add individual meeting items to an existing day does not work). Eventually you will still have to go into the database to add the correct study lessons.
So the easiest way is to open the database, find the table lmm_schedule, choose New Record and add a new line, exactly like in the picture. Of course the id will be different for each user. Close and save the database. Do not make any changes in the database, when TB is open.
[EDIT] You open the database by first going to its location (Settings - Open Database location, then close TB (!)). Use a good database editor of your choice, see my suggestion below in the signature.
For accessing the database my personal preference is http://sqlitebrowser.org/
For editing templates I now use https://code.visualstudio.com/