"RiscOsNet was written in Python and appears to require RISC OS 6 and 4.39".
What about RISC OS 5? Well the help file states "It has been developed and tested on a Castle Iyonix running RISC OS 5.0x" - amazing that drobe missed that one and only listed them ROL RISC OS flavours
Help further mentiones "It is reliant on the MiniZip library file in RISC OS Select to zip up shared downloads; MiniZip is currently not available for RISC OS 5 and appears not to work on the A9." Strange, indeed to use that since there are Zip apps around for all RISC OS variants - be it SparkFS or InfoZip.