Electrum personal server rescan-script.py

when i run the rescan script i get the following output:

Traceback (most recent call last):  File "/home/bitcoin/electrumserver/eps/rescan-script.py", line 71, in <module>    main()  File "/home/bitcoin/electrumserver/eps/rescan-script.py", line 67, in main    rpc.call("rescanblockchain", [height])  File "/home/bitcoin/electrumserver/eps/electrumpersonalserver/jsonrpc.py", line 58, in call    raise JsonRpcError(response["error"])electrumpersonalserver.jsonrpc.JsonRpcError: {'code': -32601, 'message': 'Method not found'}

I am very new to this, so please explain for beginners :).