Why doesn't the Lotus WordPro importer work in LO 4.1 or 4.2?

I have some .LWP files that I need to convert, but they are not importing. In File-open dialog, I select a type of "Lotus WordPro Document (*.LWP), but when I open the document it shows a size of 0 words/characters.
All the .LWP documetns I have tested so far show the same behavior. I get the same behavior in Win7U/64 LibreOffice 4.1.1.2; Win7U/64 LibreOffice 4.2.5; Win7S LibreOffice 4.2.5; Linux 64 bit with Libreoffice 4.1.3.2.

Did it ever work properly? If so then it is a regression in the 4.1 and 4.2 branches…

If the import filter in previous versions did work for you, I would recommend getting a portable version of an older branch (I would bet on version 3.6.7, the final version in the 3.x branch)

Personally I prefer the X-LibreOffice portable versions because you can run them simultaneously with your installed version (i.e. you can open it momentarily to do a conversion without having to close your installed version)
http://sourceforge.net/projects/winpenpack/files/X-LibreOffice/releases/

To add to what @Pedro1 has indicated, support for LWP files is sporadic. It appears to depend on the version of Lotus Smart Suite the file was created in as well as other possible factors. Refer the answer here and the list of open bugs for “lwp”. Also note that the Portuguese sample files on the Lotus FTP site here all appear to open OK, while the English equivalents here do not all open.

I don’t have an answer to your question but a possible work around.

I would download the portable version of LibO 4.1.6 from http://www.libreoffice.org/download/portable-versions/
and convert the files you have into odt-format.

I further like to ask you to please report a bug here: https://www.libreoffice.org/get-help/bug/