My cu_changes table according to the command '.schema cu_changes' produces
CREATE TABLE cu_changes ( cuc_id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, cuc_namespace INTEGER NOT NULL default '0', cuc_title TEXT NOT NULL default '', cuc_user INTEGER NOT NULL DEFAULT 0, cuc_user_text TEXT NOT NULL DEFAULT '', cuc_actor INTEGER NOT NULL DEFAULT 0, cuc_actiontext TEXT NOT NULL default '', cuc_comment TEXT NOT NULL default '', cuc_comment_id INTEGER NOT NULL DEFAULT 0, cuc_minor INTEGER NOT NULL default '0', cuc_page_id INTEGER NOT NULL default '0', cuc_this_oldid INTEGER NOT NULL default '0', cuc_last_oldid INTEGER NOT NULL default '0', cuc_type INTEGER NOT NULL default '0', cuc_timestamp TEXT NOT NULL default '', cuc_ip TEXT NULL default '', cuc_ip_hex TEXT default NULL, cuc_xff TEXT NULL default '', cuc_xff_hex TEXT default NULL, cuc_agent TEXT default NULL, cuc_private BLOB default NULL );
A number of INTEGER columns have their defaults as string values representing 0. The values need to be fixed to be the literal number 0 and any entries that have the wrong value need to be fixed.
This comes from CheckUser using mysql SQL code to make the SQLite DB. This used string 0's as the defaults.