How can I debug the OpenSSL error 'error:0906D06C:PEM routines:PEM_read_bio:no start line'?

This error signifies that OpenSSL is trying to read a PEM-encoded file (like a certificate or private key) but cannot find the expected `-----BEGIN...-----` marker. This typically points to an issue with the file's format or content. To debug: 1. Open the file in a text editor and visually inspect it. Ensure it starts with `-----BEGIN CERTIFICATE-----`, `-----BEGIN PRIVATE KEY-----`, or similar, and ends with the corresponding `-----END...-----` line. 2. Check for any extraneous characters, leading/trailing spaces, or line breaks outside these markers. 3. Verify that the file is not corrupted and is encoded in plain ASCII or UTF-8 without a Byte Order Mark (BOM). 4. If you expect a DER-encoded file, ensure you are using the correct OpenSSL command (e.g., adding `-inform DER` when applicable) as this error indicates PEM parsing.