De or het invalidering?

The correct Dutch article is:

de invalidering

Rule Words ending in -ing: almost always de. See the rule

How to use invalidering

the invalideringde invalidering
this invalideringdeze invalidering
that invalideringdie invalidering
our invalideringonze invalidering
your invalideringjouw invalidering
every invalideringelke invalidering
which invalidering?welke invalidering?
a big invalidering / the big invalideringeen grote invalidering, de grote invalidering