OS: Windows XP; upgrade from LibreOffice version 3.4 to 4.1; WRITER application.
I have some documents (.ODT) with private characters that I created using Windows application EUDCEDIT.exe. I had to create after searching all the characters in all of the fonts I have in my system, and even UNICODE charts on their website, without finding them. I needed numbers inside a “V” to simbolize an insertion and also inside an inverted “V”. It was working fine, in spite of the extra work to insert these characters in my documents through “Character Map” (chamap.exe). When I upgraded to version 4.1 these characters aren’t being displayed, it shows the infamous square for unknown character. I searched google, libreoffice help, I read dozens of documents without success with the words “unicode” “private character” “libreoffice”. One document asked the person to install a previous version because it was a bug, I installed versions 4.0.6 and 3.6 and the problem persisted. These characters show fine in Notepad.
For the reference of others there is some information on the Private Character Editor (Eudcedit.exe) here. The utility appears to be used to create fonts.
This would appear to be a font-related issue, although whether a problem with the font or LO is unclear. A sample of the font and a sample document would be required for testing to determine where the problem lies. You can upload the files elsewhere and edit your question to include a link.