[TYPO3-mvc] Fluid / Extbase - Object evaluation problem

[David Schreiber]

Hi everybody,

Finally I found out what seemed to cause my problem. I extended the
fe_users table by the columns mmfrrmarket_commodities and
mmfrrmarket_tags.

After I removed the underscore (now mmfrrmarketcommodities and
mmfrrmarkettags) and adapted my extension it seems to work.

Is it not allowed to use underscores with table columns used by
Extbase?

Regards,
David Schreiber