Paste becomes disabled after a while in Windows

[Joon Ro]

Hi,
I'm using LyX 2.1.4 in Windows 10 64bit, but I have had this issue for a while. 
If LyX has been open for a while, suddenly paste stops working - it becomes 
disabled. On the menu, the paste and paste special are greyed out, and only 
paste recent is available.
I think this is related to 
http://www.latex-community.org/forum/viewtopic.php?f=19&t=19635.
Best,Joon