[Chimera-users] How to avoid ”designate file type“ while opening a file

Hi, When I click on “file”, then “open”, no matter what types of files I am opening, there would be a window asking me to “designate file type”. This window came up very recently on my Chimera 1.13. Then I updated to Chimera 1.14 but still have this problem. Does anyone know how to avoid this? Many many thanks. Best, Zhen