Panic: http panic serving invalid memory address or nil pointer dereference

Fatal error: http panic serving invalid memory address or nil pointer dereference

2020/02/27 01:59:21 http: superfluous response.WriteHeader call from github.com/diodechain/diode_go_client/rpc.httpError (proxy.go:66)
2020/02/27 01:59:21 http: panic serving ...... : runtime error: invalid memory address or nil pointer dereference
goroutine 1612195 [running]:
net/http.(*conn).serve.func1(0xc000091360)
        /usr/local/go/src/net/http/server.go:1767 +0x139
panic(0x8ce5c0, 0xefdb00)
        /usr/local/go/src/runtime/panic.go:679 +0x1b2
github.com/gorilla/websocket.(*Conn).Close(...)
        /go/pkg/mod/github.com/gorilla/websocket@v1.4.1/conn.go:344
github.com/diodechain/diode_go_client/rpc.(*ProxyServer).pipeProxy(0xc0003cec40, 0xa03900, 0xc0000d6620, 0xc0000dea00)
        /diode_go_client/rpc/proxy.go:119 +0x3eb
net/http.HandlerFunc.ServeHTTP(0xc0002eb1a0, 0xa03900, 0xc0000d6620, 0xc0000dea00)
        /usr/local/go/src/net/http/server.go:2007 +0x44
net/http.serverHandler.ServeHTTP(0xc0000d6380, 0xa03900, 0xc0000d6620, 0xc0000dea00)
        /usr/local/go/src/net/http/server.go:2802 +0xa4
net/http.(*conn).serve(0xc000091360, 0xa04900, 0xc0000e56c0)
        /usr/local/go/src/net/http/server.go:1890 +0x875
created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:2927 +0x38e

diodechain / diode_client

Panic: http panic serving invalid memory address or nil pointer dereference #7