This is the culprit in over 70% of cases. Here is what you do:
The DLL relies on Microsoft Visual C++ runtimes. A broken runtime can cause weird “missing file” errors even when the file is present. far cry 5 fc-m64.dll missing
The fc-m64.dll error in usually happens because your antivirus has flagged and quarantined the file or the game files are corrupted. Immediate Fixes Solving the Seed Faith Crisis: How to Fix the 'FC-m64
Downloading DLL files from random websites is a common vector for malware. It is always safer to extract the file from your own game directory (via the verification method above) than to trust a file uploaded by an anonymous user. Check antivirus/quarantine