Looks like your refresh is causing the trigger to fire, but the trigger doesn't work. You will have to fix the trigger.
$ oerr ora 12008
12008, 00000, "error in materialized view refresh path"
// *Cause: Table SNAP$_<mview_name> reads rows from the view
// MVIEW$_<mview_name>, which is a view on the master table
// (the master may be at a remote site). Any
// error in this path will cause this error at refresh time.
// For fast refreshes, the table <master_owner>.MLOG$_<master>
// is also referenced.
// *Action: Examine the other messages on the stack to find the problem.
// See if the objects SNAP$_<mview_name>, MVIEW$_<mview_name>,
// <mowner>.<master>@<dblink>, <mowner>.MLOG$_<master>@<dblink>
// still exist.
$ oerr ora 1422
01422, 00000, "exact fetch returns more than requested number of rows"
// *Cause: The number specified in exact fetch is less than the rows returned.
// *Action: Rewrite the query or change number of rows requested