Silent I/O failure when missing STL container dictionary

When there is no dictionary for vector<userclass>, a class member of this type will be written to file as an empty vector. No errors or warnings are reported.
This looks like a potential data loss, quite nasty, because there is no indication something went wrong.
TAR file with a reproducer is attached, execute run.sh script to test for the bug.
Cheers,
Marcin