I have Mikrotik routerOS v4.13 with hotspot. I can normally access the FTP using windows 7. I can easily copy a single file from hotspot folder to my computer but when I try to copy the all files and folders in hotspot folder to my computer, the file transfer is stopped and the internet connection is lost. I have to restart my Buffalo router that is connected to the Mikrotik.

I used to copy several files from FTP but I don't know what happen now.

Try to copy files from different locations, where your computer is not connected over router, which should be restarted.

Try to copy files from different locations, where your computer is not connected over router, which should be restarted.

But I used to copy files normally. I can still copy single files one at a time but the problem happens when I try to copy several files that has size more than 1MB

I do not have any problems to copy all HotSpot files to my computer. As you said that router before the MikroTik does not respond, maybe you could try to load files from different locations.

I do not have any problems to copy all HotSpot files to my computer. As you said that router before the MikroTik does not respond, maybe you could try to load files from different locations.

I connect to a Mikrotik directly and it is the same.

Which FTP client do you use?
Maybe try different one, for example Filezilla?

Which FTP client do you use?
Maybe try different one, for example Filezilla?

I am just using windows folder without program

Please, try to use specific FTP program to download the files.