Oracle Solution for Error ora-15121

ORA-15121: ASM file name 'string' contains an invalid diskgroup name

What triggered the Error:

A file name was specified that did not contain a valid diskgroup name. The diskgroup name follows immediately after the ASM prefix character. It must start with an alphabetic character, and consist of up to 30 characters which are alphabetic, numeric, or the characters '$' and '_'.

What should we do to fix it:

Correct the file name specification.