Ai has this to offer. While not always accurate, it's worth a try...
"It appears that the PDF file you're trying to open in NCH Pico PDF is encrypted, which is why you're encountering the "Document encrypted" message. Since you can open the document in your browser, there are a few potential solutions you can try:
- Enter the correct password: If you know the password for the encrypted PDF, try entering it when prompted by Pico PDF.
Remove encryption in browser: If possible, open the PDF in your browser and look for an option to remove the encryption or password protection. Then save the unencrypted version and try opening it in Pico PDF.
Use browser to print to PDF: Open the encrypted PDF in your browser, then use the browser's print function to "print" the document as a new, unencrypted PDF file. Try opening this new file in Pico PDF.
Check Pico PDF settings: Ensure that Pico PDF's security settings are not blocking the file. Look for options related to "Protected Mode" or similar security features and temporarily disable them if necessary.
Update Pico PDF: Make sure you're using the latest version of Pico PDF, as older versions may have issues with certain types of encrypted PDFs.
If these solutions don't work, you may need to use a different PDF reader that is compatible with the specific encryption used in your document."