title: Sonata Admin: Can't create new object in prod
body: <p>I have a problem here with sonata admin: can't create a new object of a certain model in production environment, but it does not throw any error or exception to track the problem. When I try to create with app_dev.php enabled everything works just fine.</p>
  
  <p>Tried cleaning cache and all. Nothing happens.</p>
  
  <p>I tried this solution too: <a href="https://stackoverflow.com/questions/22248992/sonata-admin-bundle-delete-not-working-in-prod">Sonata Admin Bundle delete not working in prod</a>
  but the problem still persists.</p>
  
  <p>Symfony 2.8 with Sonata Admin in Nginx Server. Other models work fine too.</p>
  
  <p>Any help please? I have no clue where must be the problem :( </p>
  
  <p>EDIT:</p>
  
  <p>I got this in logs:</p>
  
  <p>2018/03/15 13:55:43 [error] 12984#0: *11647 NAXSI_FMT: ip="LOLip"&amp;server="lolmyweb.com"&amp;uri=/admin/product/productlink/create&amp;learning=0&amp;vers=0.55.3&amp;total_processed=13310&amp;total_blocked=35&amp;block=1&amp;cscore0=$RFI&amp;score0=8&amp;zone0=BODY&amp;id0=1101&amp;var_name0=s5aaa7b4711a0e[link], client: 80.38.196.155, server: "lolmyweb.com, request: "POST /admin/product/productlink/create?uniqid=s5aaa7b4711a0e HTTP/1.1", host: "lolmyweb.com", referrer: "lolmyweb.com/admin/product/productlink/create"</p>
  
  <p>No idea what that means...</p>