Twitter shares are down more than 11% in post market trading after the social media company released weaker-than-expected financial guidance for Q4 — casting a spotlight on its struggle to boost its users.

Analysts expected Twitter to say that it could generate $742 million in revenues in the current quarter, with EBITDA of about $199 million. But the company said that sales would come in between $695 million-and-$710 million, with adjusted EBITDA of $155 million-to-$175 million.

The company says that Q4 results will reflect one-time costs associated with its recent layoff of 8% of its workforce.

It also said that it had 320 million Monthly Active Users in Q3, which was up 11% vs the same period last year — but still lower than Wall Street’s expectation for 324 million.

Twitter’s stock closed the day at $31.30 which is down more than 39% since late April, when it disclosed weaker than expected usage and engagement numbers.

CEO Jack Dorsey remained upbeat, saying he sees “strong financial performance this quarter, as well as meaningful progress across our three areas of focus: ensuring more disciplined execution, simplifying our services, and better communicating the value of our platform. We’ve simplified our roadmap and organization around a few big bets across Twitter, Periscope, and Vine that we believe represent our largest opportunities for growth.”

The disappointing Q4 forecast obscured the Q3 numbers, which topped Wall Street expectations. Twitter generated a net loss of $131.7 million, down nearly 25% vs the same period last year, on revenues of $569.2 million, up 57.6%. The sales number beat forecasts for $559.6 million.

Adjusting for one-time expenses — including a $166 million stock-based compensation expense — the company says it generated earnings of 10 cents a share. That contrasts with expectations for a 5 cent profit per share.

This is the first report since October 5 when Twitter announced co-founder and previous interim CEO Dorsey landed the full-time job, and with former Google SVP Omid Kordestani as chairman.