base special spaces r full , i research and can build theory lab .... float over grey tab says"not enough space available" so i sold the repair bay ..... go back and float over a still grey build button and it says "base must be a level 4"
ok so either the float over needs to say "not enough space,required level 4"
or if your base isn't at a high enough rank to build a particular item.... the whole thing needs to be in red highlighted text or something
Before selling repair bay
after making space available
