Comment 19 for bug 450927

For Linux, this is very likely to be a problem with packaging for individual distros and not Inkscape itself.

For Windows, please follow the instructions in the FAQ: https://inkscape.org/learn/faq/#fantastic-lxml-wrapper-libxml2-required-inkexpy-and-therefore-extension

If there is a specific issue that is actually Inkscape's fault, please check for any open bugs, then open a new one with specific details about it. Thank you!