When you use Goldmark to speed up a construction, the production of a unit or a research project, it's very important to keep in mind that it may not instantly complete the project.
Using Goldmark will skip a certain amount of time, depending on the speed of the game, and so it may require multiple payments to successfully complete the task.

If you have attempted to spend Goldmark, but you have not seen any change in the production timer, please restart your app and check again, as there may have been an intermittent connection issue resulting in a delay. Please do not tap the button multiple times, as this may result in additional Goldmark being taken, and we would not be able to return Goldmark spent in this way.

Thank you for your understanding, and good luck out there.