[tde-users] problems with apt & aptitude

The electric power went out in my building overnight while I was asleep, having left my laptop running, and when I awoke I couldn't boot it up again, but was forced to reinstall my system. (And here was I just congratulating myself on having gone about 8 months without any major changes, much less disasters.) My installation did not go well. Maybe it's because I hadn't done it in awhile; as well as the fact that I am too busy to be bothered with this crap just now, yet I still need a working machine in order to keep my life together. In all, I think I tried 11 times (yes, eleven!) to get my system reinstalled and reconfigured. It doesn't go so well when there are other important matters that also claim my attention. The problems with reinstallation do not seem to involve Trinity as such. For some unknown reason, the XFCE desktop has messed up my settings, so that I was unable to find my network, etc.; so instead, I used MATE to finish the installation, then installed my TDE packages. After I got to that stage, I was back in familiar territory, and all seemed to be going well.... Anyway, so I got it up and running, everything looks right, just finishing up, installing all those other packages that can wait. And now, I get this weird error message: sudo apt-get -f install apt-get: symbol lookup error: /usr/lib/x86_64-linux-gnu/libapt-private.so.0.0: undefined symbol: _ZN11pkgDepCache24IncreaseActionGroupLevelEv, version APTPKG_6.0 I don't know what this means, and I am unable to use apt utilities, apt-get, aptitude, etc. I can still install packages using dpkg, but without knowing how to solve this problem, it seems pointless to keep on trying to make it work. After 11 attempts at reinstallation throughout today, I am at my wits' end, and really do not want to undertake yet another reinstallation. If anybody knows of a way to solve this issue, I will be for ever grateful. Bill