go text/template html/template invalid memory address or nil pointer dereference

2017/08/14 20:06:10 http: panic serving 172.22.27.131:56324: runtime error: invalid memory address or nil pointer dereference
goroutine 19 [running]:
net/http.(*conn).serve.func1(0xc420171e00)
        /usr/local/go/src/net/http/server.go:1693 +0xd0
panic(0x7d84a0, 0xa6d910)
        /usr/local/go/src/runtime/panic.go:491 +0x283
html/template.(*Template).checkCanParse(0xc4202e80f0, 0x0, 0x0)
        /usr/local/go/src/html/template/template.go:84 +0x45
html/template.parseFiles(0xc4202e80f0, 0xc420011250, 0x1, 0x1, 0x7b87c0, 0xc420014b01, 0xc420011250)
        /usr/local/go/src/html/template/template.go:396 +0x40
html/template.(*Template).ParseFiles(0xc4202e80f0, 0xc420011250, 0x1, 0x1, 0xd, 0xc420041a88, 0x60c3b2)
        /usr/local/go/src/html/template/template.go:390 +0x49
managerNet.listGuidance(0xa41ca0, 0xc4202ea000, 0xc4201ec300)
        /home/ubuntu/mew/mew_manager/src/managerNet/listGuidance.go:11 +0xa8
net/http.HandlerFunc.ServeHTTP(0x864fc8, 0xa41ca0, 0xc4202ea000, 0xc4201ec300)
        /usr/local/go/src/net/http/server.go:1914 +0x44
mewNet.Logger.func1(0xa41ca0, 0xc4202ea000, 0xc4201ec300)
        /home/ubuntu/mew/mew_server/src/mewNet/logger.go:38 +0x1a7
net/http.HandlerFunc.ServeHTTP(0xc42007dbc0, 0xa41ca0, 0xc4202ea000, 0xc4201ec300)
        /usr/local/go/src/net/http/server.go:1914 +0x44
github.com/gorilla/mux.(*Router).ServeHTTP(0xc420088320, 0xa41ca0, 0xc4202ea000, 0xc4201ec300)
        /home/ubuntu/go/src/github.com/gorilla/mux/mux.go:114 +0xdc
net/http.serverHandler.ServeHTTP(0xc42007f5f0, 0xa41ca0, 0xc4202ea000, 0xc4201ec100)
        /usr/local/go/src/net/http/server.go:2610 +0xb4
net/http.(*conn).serve(0xc420171e00, 0xa42360, 0xc42005c300)
        /usr/local/go/src/net/http/server.go:1797 +0x71d
created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:2711 +0x288