The phrase "major weakness" refers to a significant flaw or limitation that someone or something has. It indicates a significant area where they are not skilled or capable. Full definition
One major weakness of an index is that it has to put a large portion of its funds into the biggest companies in the index. (allfinancialmatters.com)
Unless you have obvious major weaknesses in all positions, a large turnover of players is NOT smart and it is super expensive. (justarsenal.com)
That comment was likely meant to reflect on the overall state of the company that's been extremely successful in recent times, with the smartphone segment being its only major weakness. (androidheadlines.com)