I was thinking just a google , something like
Lubuntu bug or problem or errors after update
and maybe give version numbers
Akito has solved the Lububtu forum issue
There is an Ubuntu forum, it seems to be fairly active.
There must be a place for Lubuntu bug reports.
Sounds like a filesystem problem.
You can afford to wait a long time. Most of these updates are trivial security patches which you can do without.
Is there any way you can blacklist the suspected package and allow other updates to proceed? That might not be desirable, other things may depend on that package.
If and when Lubuntu fix it, you can safely upgrade because they will replace the problem package with a new version and your update will skip the sick version.
That , by the way , saves on downloads. If you wait long intervals, you skip versions when you download.
Cheer up
Neville