There are 2 solutions, add the game to the exceptions list or stop your security program protecting the documents folder. On bitdefender if you open it and look for 'notifications' on the left look through and see if there is any mention of bio4.exe or anything that might sound like Resi 4 being blocked for accessing the protected folder.
If so they have taken to protecting folders including the documents folder where Resi 4 and several other games try to create the save games. Are you using a security suite like bitdefender?