This message is generated when a check on the form of a file to be loaded using DumpGet fails.
This message is not used in the current version of the Wolfram Language.
Files loaded using DumpGet are normally created using DumpSave on the same computer or on an equivalent computer. Files created using DumpSave are not portable between computers.
Off[message] switches off the message; On[message] switches it on. For example: Off[DumpGet::bgchk].