Hi everyone!
In "Seasons of Silver" scenario, Cyanide Leacher requires Obreras workforce also while paused. In the following screenshot the selected Cyanide Lecaher has no oxidation pools, and the building is paused.
Furthermore, it's impossible to blueprint oxidation pools when no building materials are available: the key is greyed out. This is shown as well in the screenshot: there are no construction materials, and blueprint mode is selected, but the "oxidation pool" button is greyed out and produce no result in clicking. It is possible to blueprint oxidation pools if materials for at least one pool are available.
Thanks for your patience and help!
Acidello