1018 - Integer value could not be parsed.

Description
While parsing an integer variable declaration, an error was encountered because the integer is malformed or too large to be stored as a 32-bit signed value.
Example
Config:
.MyInt = 123456789123456789
Output:
c:\Test\fbuild.bff(1):(10) FASTBuild Error #1018 - Integer value could not be parsed. .MyInt = 123456789123456789 ^ \--here
Fix:
.MyInt = 123