Filezilla on Raspbian

[#1]

I have been with PlusNet for many years. At present my PlusNet router connects two Raspberry Pi 3s, one with RISC OS, via an ethernet cable, the other with Raspbian via wireless. I use FTPc on the RISC OS machine - it has always worked without a hitch. To be able to do the same job from Raspbian I installed Filezilla. Its setup wizard lets you test the connection, but it will not connect - saying that it cannot open an answer socket. I am no Linux expert, and I must have overlooked something. But what?

[#2]

Are both TCP Ports 21 (command) and 20 (data) open? Is Filezilla using passive or active mode? Passive is probably needed.

[#3]

Thanks for the reply. I tried other FTP clients and they work OK, so I am not bothered about Filezilla. I should have tried them first before posting my query - apologies.