I am posting this here because I think this is a good place since it is a common problem, at least for me. I have accidentally opened a drawing file (not the project) in 2018 but the rest of the project is all in 2016. When I opened it up in 2016 it would not let me open the main floor drawing. This is a project that has been shared with a customer who uses 2016 and does not have 2018. Is there a way that I can get the main drawing or a version of the main drawing? Was thinking perhaps a recovery file or similar.
Side note I wish that Softplan had some sort of way to save files backwards or at least really make sure that it is where you want to open it. It seems that people use a lot of different versions and could cause problems. Or at least Softplan give me a reason why you dont.