The problem arises with the games from Ubisoft, such as Heroes, Assassin's Creed or Far Cry, while it doesn't matter, you have a licensed game or not, and the reason is the same as in the case of Cryea.dll file (in Crysis 3 game).
Fixing the problem "UbiorBitapi_r2.dll is missing"
In fact, you do not need to search where download ubiorBitapi_r2.dll files and ubiorbitapi_r2_loader.dll and where to throw this file: Because your antivirus will again find the virus in this file and deletes it or placed in quarantine.
The correct solution to the problem with the launch of the game due to the lack of UbiorBitapi_r2 libraries - disable the automatic actions of your antivirus (or disable it) and reinstall the game. When your antivirus is reported that a virus is found in ubiorbitapi_r2.dll or ubiorbitapi_r2_loader.dll, skip this file and add it to an antivirus elimination (or do it until the antivirus is disabled, then turn on again) so as not to receive the alert that he is absent. It should be done similarly if the antivirus does not like any other files from Ubisoft Game Launcher.
The fact is that this file, even from the original disk with a licensed game or when downloading the game in Steam, many antiviruses are perceived as a malicious software (in my opinion, like Troyan). This is due to the fact that the Ubisoft games use a kind of protection against the unauthorized use of their products.
In general, it looks like this: the executable game file is encrypted and packaged, and when it starts using UbiorBitapi_R2_loader.dll, decoding and room executable code in the computer memory occurs. Such behavior is just characteristic of many viruses, from here and quite predictable reaction of your anti-virus software.
Note: All of the above concerned, above all, licensed versions of games.