: By design, there is no official tool or method to convert a .p file back into its original .m source file. Risks of "Decoder" Archives (e.g., .7z files)

file are bundled with malware or require suspicious "activation" steps. Legal Implications:

If you know what the P-code does (by running it with various inputs), you can reverse-engineer the without touching the encryption. This is legal under clean-room reverse engineering in some jurisdictions (consult a lawyer).

: The most reliable way to get the source code is to request the original file from the developer who created the P-code. Use the Debugger

However, before you download that suspicious archive from a file-sharing site, it is critical to understand what MATLAB P-code actually is, why a generic 7z archive claiming to decode it is almost certainly a trap, and the legitimate paths available to recover your work.