Possibly you had a corrupt download of the ISO? Did you download the 64-bit English ISO?
If so, it is as follows:
17763.3650.221105-1748.rs5_release_svc_refresh_SERVER_EVAL_x64FRE_en-us.ISO
Algorithm Hash
SHA256 6DAE072E7F78F4CCAB74A45341DE0D6E2D45C39BE25F1F5920A2AB4F51D7BCBB
If it matches, try another bootable media and make sure it boots off that media. If it does not, clear your web browser cache and redownload the file.
If you have access to another computer, try the bootable media and see if it works on that device or produces the same error.