Missing error message when trying to create duplicate page title

[its moi]

We currently (I do not know since when exactly) have the problem that when trying to create a page with a title that exists in given space, there is no error message coming up when saving. Instead the loading progress icon will start to move forever. 

We are using 6.13.8 on Server. I am sure that there was an error message coming up in these cases which obviously makes much more sense. Does anybody know what the reason could be? 

[Fabian Lim]

Hi Moi,

I haven't been able to reproduce this one in the newer versions.  Have you been able to upgrade?

Regards