The error fcm64.dll missing (properly named fc_m64.dll) typically occurs in
Causes of the FCM64.DLL Missing Error
A sterile white dialogue box popped up like a jump scare:"The code execution cannot proceed because fcm64.dll was not found."
Look for FC_m64.dll or similar files. Select Actions > Restore.
Add an Exclusion: To prevent the file from being deleted again, add your Far Cry 5 game folder to your antivirus Exclusion/Exceptions list.