signing Q's from users' account page goes to error page

[davidmooreppf]

From random user's page ::

http://www.askthem.io/users/5307b227ec8d83040f000011/signatures

... signed-in to my admin acc't, I clicked "sign" on the button ::

http://www.askthem.io/users/5307b227ec8d83040f000011/signatures#

... and got an error page ::

http://www.askthem.io/users/questions/5307b227ec8d83040f000010?share=true

... after I clicked back in my browser, trying again to click the "sign" button does nothing, no response.

Similarly, from @maryamgunja page ::

http://www.askthem.io/users/52e69c3df92ea19a1a000027

... clicking on "sign" next to David Brooks Q ::

http://www.askthem.io/unaffiliated/questions/52ebc992f92ea1aa81000008

... goes to error page ::

http://www.askthem.io/users/questions/52ebc992f92ea1aa81000008?share=true

... same from her page of signatures, goes to error page ::

http://www.askthem.io/users/questions/52ebe552ec8d83d75100000f?share=true