File Upload Issue

I have noticed that when you attempt to upload a file (that is not allowed) that it continues to look like its uploading. And does NOT tell you its a "not allowed" extension until the very end.

So, if the file is large, the user is waiting and waiting thinking its uploading.

The "file extension not allowed" prompt should come IMMEDIATE when they attempt to upload.

I know what you mean.

You wait wait wait and wait thinking it's going be all good then nothing.

I see a bigger pattern here but I just can't put my finger on it.