What version of Go are you using (go version)?

$ go version
go1.14.5 darwin/amd64
gopls 0.4.4

Does this issue reproduce with the latest release?

Yes?

What operating system and processor architecture are you using (go env)?

$ go env
(valid build configuration = false)
(build flags: [])
GOINSECURE=
GOPATH=/Users/me/go
GOROOT=/usr/local/Cellar/go/1.14.5/libexec
GO111MODULE=
GONOPROXY=
GOPROXY=https://proxy.golang.org,direct
GOSUMDB=sum.golang.org
GOCACHE=/Users/me/Library/Caches/go-build
GOMOD=
GOMODCACHE=
GONOSUMDB=
GOPRIVATE=
GOFLAGS=

What did you do?

1. Open a go file in VSCode
2. Trigger Go: Restart Language Server from the command palette

What did you expect to see?

In the go server logs, there should be no:

gopls: failed reading header line: EOF

message

What did you see instead?

I see the aforementioned message in the logs and the server is exiting with exit code 2.

I think the relevant code is here:
https://github.com/golang/tools/blob/cc40288be83943c50bf80a9702fb35bd5e580e8d/internal/jsonrpc2/stream.go#L110-L114
And the problem might be that it's not doing what the comment there says. The comment says:

// read the header, stop on the first empty line

but since the s.in.ReadString('\n') call is looking for a newline, I think it will return non-nil err when it sees an empty line. Thus we'll never get to the graceful, empty-line handling lower in the code.