This issue is caused by the amount of Research Expansions you have already placed in your city. For some reason, some players had more Research Expansions in their city than they had actually researched. We have fixed that issue with our last update (to version 0.15). It is now also impossible to place those "extra" research expansions that you should not have had in the first place - after the update, the game now checks the amount of expansions you can place before actually placing it. As you already have the correct amount (or in some cases: more than would be the correct amount), you cannot place even more. The Build Menu still displays the expansion as "available", though, which makes it a bit confusing. Premium Expansions and Province Expansions are not affected by this issue.
We hope to have been able to clear up the cause of this issue a bit now. We do apologise for the inconvenience caused by it. Should you have any other questions, you can ask them here or contact our support.