The popup for the worker is Not enough workers. Given you have 90k people, I would say this is because you have a large amount of office buildings which are taking up your jobs. Try going into Policies and setting Schools Out, which may help bring more jobs into your city. Also build the Hadron Collider if you are prepared for a massive increase in unemployment, over time this will also fix it.
The other problem is Not enough buyers. This (as well as most other problems with industry) can be fixed by providing cargo transportation to your industry such as cargo trains, cargo harbours or, in the Industries DLC, cargo airports. Try and keep your cargo trains and passenger trains separate. Also take a look at your traffic.