diff --git a/autoload/OmniSharp.vim b/autoload/OmniSharp.vim
index 2db515719..6354e5afa 100644
--- a/autoload/OmniSharp.vim
+++ b/autoload/OmniSharp.vim
@@ -12,21 +12,20 @@ function! OmniSharp#GetHost(...) abort
   let bufnr = a:0 ? a:1 : bufnr('%')
   if g:OmniSharp_server_stdio
     " Using the stdio server, b:OmniSharp_host is a dict containing the
-    " sln_or_dir:
-    " { 'sln_or_dir': '/path/to/solution_or_dir' }
+    " `sln_or_dir` and an `initialized` flag indicating whether this buffer has
+    " successfully been registered with the server:
+    " { 'sln_or_dir': '/path/to/solution_or_dir', 'initialized': 1 }
     let host = getbufvar(bufnr, 'OmniSharp_host', {})
     if get(host, 'sln_or_dir', '') ==# ''
       let host.sln_or_dir = OmniSharp#FindSolutionOrDir(1, bufnr)
+      let host.initialized = 0
       call setbufvar(bufnr, 'OmniSharp_host', host)
     endif
     " The returned dict includes the job, but the job is _not_ part of
     " b:OmniSharp_host. It is important to always fetch the job from
     " OmniSharp#proc#GetJob, ensuring that the job properties (job.job_id,
     " job.loaded, job.pid etc.) are always correct and up-to-date.
-    return {
-    \ 'sln_or_dir': host.sln_or_dir,
-    \ 'job': OmniSharp#proc#GetJob(host.sln_or_dir)
-    \}
+    return extend(copy(host), { 'job': OmniSharp#proc#GetJob(host.sln_or_dir) })
   else
     " Using the HTTP server, b:OmniSharp_host is a localhost URL
     if empty(getbufvar(bufnr, 'OmniSharp_host'))
diff --git a/autoload/OmniSharp/actions/buffer.vim b/autoload/OmniSharp/actions/buffer.vim
index 863020e22..fbd611788 100644
--- a/autoload/OmniSharp/actions/buffer.vim
+++ b/autoload/OmniSharp/actions/buffer.vim
@@ -5,13 +5,17 @@ set cpoptions&vim
 " returned (synchronously or asynchronously)
 function! OmniSharp#actions#buffer#Update(...) abort
   let opts = a:0 && a:1 isnot 0 ? { 'Callback': a:1 } : {}
-  if !OmniSharp#IsServerRunning() | return | endif
+  let initializing = a:0 > 1
   if bufname('%') ==# '' || OmniSharp#FugitiveCheck() | return | endif
-  if b:changedtick != get(b:, 'OmniSharp_UpdateChangeTick', -1)
+  if initializing ||  b:changedtick != get(b:, 'OmniSharp_UpdateChangeTick', -1)
     let b:OmniSharp_UpdateChangeTick = b:changedtick
     if g:OmniSharp_server_stdio
+      if initializing
+        let opts.Initializing = 1
+      endif
       call s:StdioUpdate(opts)
     else
+      if !OmniSharp#IsServerRunning() | return | endif
       call OmniSharp#py#Eval('updateBuffer()')
       call OmniSharp#py#CheckForError()
       if has_key(opts, 'Callback')
@@ -25,6 +29,9 @@ function! s:StdioUpdate(opts) abort
   let opts = {
   \ 'ResponseHandler': function('s:StdioUpdateRH', [a:opts])
   \}
+  if has_key(a:opts, 'Initializing')
+    let opts.Initializing = 1
+  endif
   call OmniSharp#stdio#Request('/updatebuffer', opts)
 endfunction
 
diff --git a/autoload/OmniSharp/actions/workspace.vim b/autoload/OmniSharp/actions/workspace.vim
index 6ea9b493c..1bb592107 100644
--- a/autoload/OmniSharp/actions/workspace.vim
+++ b/autoload/OmniSharp/actions/workspace.vim
@@ -5,8 +5,7 @@ let s:attempts = 0
 
 function! OmniSharp#actions#workspace#Get(job) abort
   let opts = {
-  \ 'ResponseHandler': function('s:ProjectsRH', [a:job]),
-  \ 'AllowUnloaded': 1
+  \ 'ResponseHandler': function('s:ProjectsRH', [a:job])
   \}
   let s:attempts += 1
   call OmniSharp#stdio#RequestGlobal(a:job, '/projects', opts)
diff --git a/autoload/OmniSharp/buffer.vim b/autoload/OmniSharp/buffer.vim
index 8dbdc8f36..62a32dff8 100644
--- a/autoload/OmniSharp/buffer.vim
+++ b/autoload/OmniSharp/buffer.vim
@@ -1,6 +1,32 @@
 let s:save_cpo = &cpoptions
 set cpoptions&vim
 
+function! OmniSharp#buffer#Initialize(job, bufnr, command, opts) abort
+  let a:job.pending_requests = get(a:job, 'pending_requests', {})
+  let host = getbufvar(a:bufnr, 'OmniSharp_host')
+  if get(host, 'initialized') | return | endif
+  let a:job.pending_requests[a:bufnr] = get(a:job.pending_requests, a:bufnr, {})
+  " More recent requests to the same command replace older pending requests
+  let a:job.pending_requests[a:bufnr][a:command] = a:opts
+  if has_key(OmniSharp#GetHost(a:bufnr), 'initializing') | return | endif
+  let host.initializing = 1
+  let Callback = function('s:CBInitialize', [a:job, a:bufnr, host])
+  call OmniSharp#actions#buffer#Update(Callback, 1)
+endfunction
+
+function! s:CBInitialize(job, bufnr, host) abort
+  let a:host.initialized = 1
+  unlet a:host.initializing
+  call OmniSharp#log#Log(a:job, 'Replaying requests for buffer ' . a:bufnr)
+  for key in keys(a:job.pending_requests[a:bufnr])
+    call OmniSharp#stdio#Request(key, a:job.pending_requests[a:bufnr][key])
+    unlet a:job.pending_requests[a:bufnr][key]
+    if empty(a:job.pending_requests[a:bufnr])
+      unlet a:job.pending_requests[a:bufnr]
+    endif
+  endfor
+endfunction
+
 function! OmniSharp#buffer#PerformChanges(opts, response) abort
   if !a:response.Success | return | endif
   let changes = get(a:response.Body, 'Changes', [])
diff --git a/autoload/OmniSharp/project.vim b/autoload/OmniSharp/project.vim
index ef2abcefe..658634275 100644
--- a/autoload/OmniSharp/project.vim
+++ b/autoload/OmniSharp/project.vim
@@ -2,13 +2,13 @@ let s:save_cpo = &cpoptions
 set cpoptions&vim
 
 function! OmniSharp#project#CountLoaded() abort
-  " TODO: stdio guard?
+  if !g:OmniSharp_server_stdio | return 0 | endif
   let host = OmniSharp#GetHost()
   return get(OmniSharp#proc#GetJob(host.sln_or_dir), 'projects_loaded', 0)
 endfunction
 
 function! OmniSharp#project#CountTotal() abort
-  " TODO: stdio guard?
+  if !g:OmniSharp_server_stdio | return 0 | endif
   let host = OmniSharp#GetHost()
   return get(OmniSharp#proc#GetJob(host.sln_or_dir), 'projects_total', 0)
 endfunction
@@ -22,12 +22,6 @@ function! OmniSharp#project#RegisterLoaded(job) abort
   endif
   let a:job.loaded = 1
   silent doautocmd <nomodeline> User OmniSharpReady
-
-  " TODO: Remove this delay once we have better information about
-  " when the server is completely initialised:
-  " https://github.com/OmniSharp/omnisharp-roslyn/issues/1521
-  call timer_start(1000, function('OmniSharp#stdio#ReplayRequests', [a:job]))
-  " call OmniSharp#stdio#ReplayRequests(a:job)
 endfunction
 
 " Listen for stdio server-loaded events
diff --git a/autoload/OmniSharp/stdio.vim b/autoload/OmniSharp/stdio.vim
index 22bb33d36..1a3dd59aa 100644
--- a/autoload/OmniSharp/stdio.vim
+++ b/autoload/OmniSharp/stdio.vim
@@ -3,7 +3,6 @@ set cpoptions&vim
 
 let s:nextseq = get(s:, 'nextseq', 1001)
 let s:requests = get(s:, 'requests', {})
-let s:pendingRequests = get(s:, 'pendingRequests', {})
 
 function! OmniSharp#stdio#HandleResponse(job, message) abort
   try
@@ -100,17 +99,37 @@ function! OmniSharp#stdio#Request(command, opts) abort
     let [bufnr, lnum, cnum] = s:lastPosition
   elseif has_key(a:opts, 'BufNum') && a:opts.BufNum != bufnr('%')
     let bufnr = a:opts.BufNum
-    let lnum = 1
-    let cnum = 1
+    let lnum = get(a:opts, 'LineNum', 1)
+    let cnum = get(a:opts, 'ColNum', 1)
   else
     let bufnr = bufnr('%')
-    let lnum = line('.')
-    let cnum = col('.')
+    let lnum = get(a:opts, 'LineNum', line('.'))
+    let cnum = get(a:opts, 'ColNum', col('.'))
   endif
-  let job = OmniSharp#GetHost(bufnr).job
+  let host = OmniSharp#GetHost(bufnr)
+  let job = host.job
   if !OmniSharp#proc#IsJobRunning(job)
     return
   endif
+
+  if has_key(a:opts, 'Initializing')
+    " The buffer is being initialized - this request will always be sent
+  else
+    if !get(host, 'initialized')
+      " Replay the request when the buffer has been initialized with the server
+      let opts = extend(a:opts, {
+      \ 'BufNum': bufnr,
+      \ 'LineNum': lnum,
+      \ 'ColNum': cnum
+      \})
+      if has_key(opts, 'UsePreviousPosition')
+        unlet opts.UsePreviousPosition
+      endif
+      call OmniSharp#buffer#Initialize(job, bufnr, a:command, opts)
+      return 0
+    endif
+  endif
+
   if has_key(a:opts, 'SavePosition')
     let s:lastPosition = [bufnr, lnum, cnum]
   endif
@@ -156,15 +175,6 @@ function! OmniSharp#stdio#RequestGlobal(job, command, opts) abort
 endfunction
 
 function! s:Request(job, body, command, opts, ...) abort
-  let sep = a:0 ? a:1 : ''
-  if !has_key(a:opts, 'AllowUnloaded') &&
-  \ (!has_key(a:job, 'job_id') || !a:job.loaded)
-    if has_key(a:opts, 'ReplayOnLoad') && !has_key(s:pendingRequests, a:command)
-      " This request should be replayed when the server is fully loaded
-      let s:pendingRequests[a:command] = a:opts
-    endif
-    return 0
-  endif
   call OmniSharp#log#Log(a:job, 'Request: ' . a:command, 1)
 
   let a:body['Command'] = a:command
@@ -173,6 +183,7 @@ function! s:Request(job, body, command, opts, ...) abort
   if has_key(a:opts, 'Parameters')
     call extend(a:body.Arguments, a:opts.Parameters, 'force')
   endif
+  let sep = a:0 ? a:1 : ''
   if sep !=# ''
     let encodedBody = substitute(json_encode(a:body), sep, '\\r\\n', 'g')
   else
@@ -196,14 +207,6 @@ function! s:Request(job, body, command, opts, ...) abort
   return 1
 endfunction
 
-function! OmniSharp#stdio#ReplayRequests(job, ...) abort
-  call OmniSharp#log#Log(a:job, 'Replaying requests')
-  for key in keys(s:pendingRequests)
-    call OmniSharp#stdio#Request(key, s:pendingRequests[key])
-    unlet s:pendingRequests[key]
-  endfor
-endfunction
-
 let &cpoptions = s:save_cpo
 unlet s:save_cpo