If you are using the AssemblyFileVersion attribute to mark your compiled assemblies with specific Win32 file version numbers, you may get a compiler warning with certain revision numbers. The compiler warning looks like this:

warning CS1607: Assembly generation -- The version '' specified for the 'file version' is not in the normal 'major.minor.build.revision' format.

This warning is documented as occurring when the version string is not in the major.minor.build.revision format, but does not explain why it happens for the example above.

Frans Bouma updated his existing post with the reason why. The revision part of the version number must not exceed 65535 (ie. a 16-bit number). If it does, the compiler generates the warning. The MSBuild Team posted about the same thing, but also provided the fact that it is the underlying operating system that imposes this limit.