When saving a file using LibreOffice Writer, if you cut and paste the password from a non-text based file (.odt), the saved file will not be able to be opened if the password is manually typed in or cut-and pasted from a text (.txt) document, resulting in an incorrect password error. However, if the password is cut-and-pasted from the original non-text document, the file will open.
It appears that some non-visible text attributes such as font are being used in the password that causes a password cut-and-pasted from a rich text document to be treated differently than one typed in.
One method to re-create this error: Create a password with APG and save it in a ODT document with LibreOffice. Open the created file with the password in Ocular, and save the file with password by pasting in the password. Then attempt to open the file and manually type in the password; this will fail. Paste the password again using the same method in Okular and the file will open.
Impact: Persons not realizing this scenario may experience loss of data when their password fails to work.
Please disregard -- upon further testing the error is with Okular and not Libreoffice.