Cant find exact error reason in loading by WWW

The logic is - at some actions I need to load up to 15 textures using WWW in couroutine, set the preview sprite image in UI, and after other action totally remove it from memory.
Looks like I free the memory from useless textures, but anyway sometimes get that error.

Actually, I cant understand what can be wrong, because in WebPlayer build everything works fine.
Here is the second screen of same error in Chrome inspector

Anybody got some ideas what can it be?

Can you file a bug?

Sorry, but do you mean exactly?

Can you submit a bug report: Unity QA: Building quality with passion

Ok, I will do it. But I am not sure that it a bug… may be it is my fault
Reported. Hope that will help