I spent some time setting up Active Transfer MFT on the free trial version 9.10 and found that there is an issue with it. Even if you install the latest MFT 9.8 fix on it, you still end with with another error about the communication between WmMFT and IS. Looks like there is some with image file w.r.t to Active Transfer Server/Gateway.
Hence you have to download the fresh image from SAG empower and install. Currently I have not faced any issues so far. I will keep you posted if I find any.
It seems to be the error is typically seen if ActiveTransfer (WmMFT) is NOT installed on the default Integration Server instance.
ActiveTransfer can only be used with the default instance of Integration Server.
The ActiveTransfer package must only be installed on the default Integration Server instance. Please check these points and also provide the complete error logs for further investigating.