i have that problem since 0.72 and still on 0.76 the same. x64
in preference update check set every month but that message appear on every lunch of the program, really annoying
I find out the problem was with name of .exe files, i update xnviewmp in same folder and there two .exe file xnviewmp.exe(new) and xnview.exe(old)
You rename it in 0.72.1?