Why aren't there any movies on the Warrior Cats series?

There are currently no planned Warriors movies or plans to make any, despite common rumors that have spread across the Warriors community.

As her answer to the main question of a movie possibility, Victoria Holmes replied:

Okay, this is a really important issue to clear up. I'm sorry to say that there are NO plans for a Warriors movie, even though we have had lots and lots of discussions with major film companies about this. This isn't to say that there will NEVER be a Warriors movie, but please don't get your hopes up! The reason for this is that the animated movies around at the moment tend to be larger-than-life, laugh-out-loud family films that adults can laugh at as well as kids - think Shrek or Cars. A Warriors movie would be much more serious, dealing with big issues like death and loyalty, which doesn't translate well to conventional animation just now. It might fit with a manga-style approach, but there isn't a mainstream market for this in the film world just yet. So we'll have to keep our fingers crossed!