The error "/libexec/ld-elf.so.1: Shared object 'libc.so.6' not found" typically occurs when you try to run a program compiled for a different version of the operating system on FreeBSD. This error message indicates that the program is trying to use a library (in this case, libc.so.6) that is not present on the system, or is not compatible with the version of FreeBSD you are running.
To resolve this error, you will need to either:
Install the required library on your system. If the program you are trying to run is compiled for a different version of FreeBSD, you may need to install the library files for that version in order to run the program.
Re-compile the program for your version of FreeBSD. If you have the source code for the program, you can try re-compiling it for your version of FreeBSD using the gcc or clang compiler.
Find a version of the program that is compiled for your version of FreeBSD. If you don't have the source code for the program, you may need to find a version of the program that is compiled for your version of FreeBSD, or contact the developers of the program to ask for a version that is compatible with your system.
It's also possible that the error is caused by a problem with the ld-elf.so.1 file itself. In this case, you may need to try restoring the file from a backup or reinstalling the operating system.