When using the MIFimporter it seems it checks whether a given database source (like uniprot) is known by the system. When not it prompts the user for an URL for the unknown database.
The problem occurs when loading more than one PSI-MI files. Each time a new file is parsed, the unknown database URLs must be given again, but of course, because they are already present there is a warning message:
QSqlDatabasePrivate::addDatabase: duplicate connection name 'idgenerator', old connection removed.
The error occurred when trying to load the human_ewing-2007 dataset from IntAct (psi v1.0) from
ftp://ftp.ebi.ac.uk/pub/databases/intact/current/psi1/species
which is splited in 4 files.