Remove and redownload Grimoire: https://www.mpgh.net/forum/showthread.php?t=1340281
Also check the part below the big red "Errors?":
"If you have any problems running Grimoire, make sure the following is installed on your computer:
.NET Framework (4.5 or higher)
Flash Player ActiveX"
If that's not it, does it happen with any bot you download?