WALDBRAND is having problem with fuel because your population is over 600 and you are just importing coal, not producing. You can export/import coal 50 per month for a total of 600 per year. That's why you now have a problem with it. Building many trading posts will not help you import more or export more; 50 on each stuff can be traded monthly. If you are producing more than 600 per year on 1 item, you will end up having many warehouses/granaries. Use a packing station to get coal in exchange for whatever you have there, like planks or rye/bread.
WALDBRAND is having problem with fuel because your population is over 600 and you are just importing coal, not producing. You can export/import coal 50 per month for a total of 600 per year. That's why you now have a problem with it. Building many trading posts will not help you import more or export more; 50 on each stuff can be traded monthly. If you are producing more than 600 per year on 1 item, you will end up having many warehouses/granaries. Use a packing station to get coal in exchange for whatever you have there, like planks or rye/bread.