Faild to build web player?

I am getting Errors when building for web/steamed or not, while I can successfully build standalone PC/Mac versions fine. is there a different requirement/Limitation for web?

The issue normally appears after a scene/project has been worked on for a while , I find exporting the scene content as packages and import back to a brand new project sometimes fix the problem, but there are cases it just wont build for web, even just with some mesh and textures (both not very light - is this the problem?)

Thanks

I am on Xp 64bit , Unity pro

sorry , don't know if I can edit the original question. here is the error I get from the console.

Error building Player: Building stream file failed. UnityEditor.BuildPipeline:BuildPlayerInternalNoCheck(String[], String, BuildTarget, BuildOptions) UnityEditor.BuildPipeline:BuildPlayerInternalNoCheck(String[], String, BuildTarget, BuildOptions) UnityEditor.BuildPlayerWindow:BuildPlayerWithDefaultSettings(Boolean, BuildOptions) UnityEditor.BuildPlayerWindow:OnGUI() System.Reflection.MonoMethod:InternalInvoke(Object, Object[]) System.Reflection.MonoMethod:InternalInvoke(Object, Object[]) System.Reflection.MonoMethod:Invoke(Object, BindingFlags, Binder, Object[], CultureInfo) System.Reflection.MethodBase:Invoke(Object, Object[]) UnityEditor.HostView:Invoke(String) UnityEditor.HostView:OnGUI()

[....\Editor\Src\Commands\BuildPlayerUtility.cpp line 1061]

Ok, This time , I am answering my own question , if that's not against rule.

the problem has been solved by exporting every dependencies out as unitypackage and import them back into a brand new project, also best to be a local project rather than on a network drive, this way the project published to web just fine.