Troubleshoot invalid PDF page selections, encrypted files and mismatched printed page numbers before creating and checking a corrected extract.
Separate input errors from file errors
A message about page numbers usually means the source was read but the selection is invalid. A message saying the PDF cannot be opened points to a different issue, such as encryption, damage or an unsupported file.
Start by opening the source in your usual PDF viewer. If it fails there too, obtain a fresh copy when available. Changing the filename extension cannot repair a damaged document or turn another file type into a valid PDF.
Check the selection syntax
Use positive whole-number positions separated by commas, with ascending ranges where appropriate. For a ten-page source, 1, 3-5, 10 is valid. Positions such as zero or eleven are outside the document, and 5-3 is a reversed range.
Do not leave blank entries between commas. Decimal numbers and chapter names are also invalid. When the input is accepted but the output contains the wrong material, compare the chosen positions with the source rather than repeatedly changing the punctuation.
Review source limitations
Split PDF accepts unencrypted files up to 30 MB and 500 pages. Password-protected and encrypted documents are rejected; there is no password-entry feature. A document can be encrypted even if a viewer appears to open it without asking for a password.
Large or complex PDFs can also exceed a device's available memory. Close unnecessary applications if appropriate and try a simpler source. Do not assume the tool saved a completed extract when the page closed before a download became available.
Verify a successful retry
After correcting the problem, generate and download the new selection. Check its page count, first page and final page. If you changed the selected positions after creating an earlier result, make sure you are opening the latest download. Keep the original file so that additional extracts can be created without depending on an incomplete or incorrectly selected intermediate document.