What the hell is that ProcessingExports?

Hello everyone,
I have an issue saving my level. Saving takes so long. In the progress bar it shows “ProcessingExports”. Do you know what processing exports is? I thing the problem is landscape and level file is so big than i expected (almost 350mb). Can you advise me about this?
Thanks.

If anyone is having this same problem, try disabling or closing your anti-virus software.