That's not my understanding. Jean-Louis Dupont brought a case before the European Commission on behalf of Football Agent Daniel Striani.
However they told Dupont that he'd skipped several steps & needed to start from a local magistrates, before pursuing the case further up the ladder if he doesn't get his desired ruling which he did.
The European Commission rejected his case based on a specific technicality. He objected to FFP from a players & agents perspective, whilst the EC opined that FFP was directed at football clubs, & that none had complained to them about FFP over the four years it had been in effect.
No big clubs wanted to be seen as his backers to the case, albeit smaller clubs dreaming of becoming the next PSG, Leipsig or City stood to benefit.
The situation would be wholly different if football clubs brought a case to the EC or ECJ instead of football agents on behalf of players. That's all that's standing in the way of a serious court challenge to FFP.