My game and economy was running well untill major factions decide to build several shipyards in the same time.
Building them and then filling with resources completely drained their budget (they oscilate around 0 Cr). To make things worse they decided that despite money problems it is good idead to keep upgrading these shipyards (which they can't because they can't afford construction materials).

This also makes that their other stations fail, because they cannot buy or produce anything.
Also before that they went on capture spree and all these captured stations also drain their pockets.

I think you need to implement some kinds of safety measure:
- if faction budget is low they should shutdown surplus stations (e.g. if they have two shipyards, one should stop buying resources, if thay have multiple steel plants they should shut down resources buy AND production for some of them)
- factions shouldn't build nor upgrade stations if low on money
- it should be fossible for faction to sell surmplus stations to factions with better monetary reserves.
- maybe it would be nice to put stations for auction where player and NPC can bid to buy stations.