extensions don't work

Hello guys,

I have following problem:
I tried to install writer2latex as an extension. The installation was successful, but the expected option in file>export did not show up. I activated the right Java version in Tools>Options, I use Ubuntu 14.04 64 bit and libreoffice 4.2.8.
Then I tried to install some other extensions, which have all been installed without problems, but no one worked as they should.

Does anybody have an idea what the problem is?

Thanks,
Nils

Verified you have the same Java version as LibreOffice both 32 bits or both 64 bits.