Very seldom these solutions meet the needs of old people.

Explanation

This is the error. In English, adverbs are usually placed before the main verb but after auxiliary verbs (such as be, have, may, & must). The only exception is when the main verb is "to be", in which case the adverb goes after the main verb. So, here the adverb (very seldom) will be used before the verb (meet). Therefore, it should be "These solutions very seldom meet " instead of " very seldom these solutions meet". This is an example of misplaced modifier where the modifier/adverb is present but is very far away from its verb so it should be placed next to "meet", not to "these solutions", since it is describing "meet" not "these solutions"So, the corrected sentence is: "These solutions very seldom meet the needs of old people.