If you pass like "C:\Users\Music\6d4d6e0d-62b5-4d11-b55e-72ff65993492.m4a" string in double quotes then json_encode convert hexadecimal portion after back slash, so result is C:\Users\Music\u0006d4d6e0d-62b5-4d11-b55e-72ff65993492.m4a . use single quotation or double slash working fine. This is because PHP behaviour so this may be fix on future PHP version but this is very critical to convert string automatically.
If you pass like "C:\Users\Music\6d4d6e0d-62b5-4d11-b55e-72ff65993492.m4a" string in double quotes then json_encode convert hexadecimal portion after back slash, so result is C:\Users\Music\u0006d4d6e0d-62b5-4d11-b55e-72ff65993492.m4a . use single quotation or double slash working fine. This is because PHP behaviour so this may be fix on future PHP version but this is very critical to convert string automatically.