This often happens when trying to run software compiled for different systems or architectures, such as when executing the programs on a SunOS 4.1 system, or when trying to execute SPARC-specific programs on an IA machine. This error can also occur if the Binary Compatibility Package was not installed.
Make sure that the software matches the architecture and system you are using. The file(1) command can help you determine the target architecture. If you are using SunOS 4.1 software on a later release, make sure that the Binary Compatibility Package is installed. You can check for it using this command:
$ pkginfo | grep SUNWbcp
A request was made to execute a file that, although it has the appropriate permissions, does not start with a valid format.
The symbolic name for this error is ENOEXEC, errno=8.
See the a.out(4) man page for a description of executable files.