There's nothing we can do on our side, if an antivirus wrongly decides that, the same program that always worked up to the day before, has now become a virus, the program it's obviously wrong, and need to be fixed.
That's why almost all antivirus software have options to disable a certain file from scanning. The issue is, I think that McAfee, in the personal edition of the product, has stopped to include this crucial feature. I don't know if the fixed it, because it's a wrong design decision. I'm not sure of this, but I've heard the same problem on Flight1's forum, that McAfee detected their software as a virus, but doesn't offer the chance for the user to exclude the file from scanning and fix false positive reports.
If your version can do this, you should be ok by adding the FSX\fsdreamteam\Couatl\Couatl.exe file to the excluded files list, otherwise I don't see any other option than to switching to different antivirus, like the free AVG for example, that has this option even in the free version.
Note that, ALL our programs, including Couatl.exe, are digitally signed from us. This means, you can check the program integrity by right-clicking on it, select "Properties" and check the Digital Signature. If this one is reported as valid, you can be sure the executable hasn't been altered in any way. If it catched a virus (for example, one that was already in your system and attached to it), the digital signature would not be valid anymore so, you have a mean to ensure the file is clean, even without using the antivirus.