diff --git a/src/protocol/LSP.Basic.pas b/src/protocol/LSP.Basic.pas
index c36c0b3..b96bcd1 100644
--- a/src/protocol/LSP.Basic.pas
+++ b/src/protocol/LSP.Basic.pas
@@ -1107,7 +1107,9 @@ procedure TDiagnostic.Assign(Source : TPersistent);
     Severity:=Src.severity;
     Code:=Src.Code;
     self.Source:=Src.Source;
-    if Src.source.HasValue then
+    // source is a TOptionalString class and stays nil when unset;
+    // guard before dereferencing to avoid an access violation.
+    if Assigned(Src.source) and Src.source.HasValue then
       Message:=Src.Source.Value;
     end
   else
diff --git a/src/serverprotocol/PasLS.General.pas b/src/serverprotocol/PasLS.General.pas
index 606f1d5..7ca3c58 100644
--- a/src/serverprotocol/PasLS.General.pas
+++ b/src/serverprotocol/PasLS.General.pas
@@ -252,13 +252,20 @@ procedure TInitialize.ShowConfigStatus(Params: TInitializeParams; CodeToolsOptio
   I: Integer;
   FPCOptions: TStringArray;
 begin
-  if Params.clientInfo.version.HasValue then
+  // clientInfo and its version are optional in the LSP spec; both may be
+  // nil here (TOptionalString is a class that stays nil when the client
+  // omits the field), so guard before dereferencing.
+  if Assigned(Params.clientInfo) and Assigned(Params.clientInfo.version)
+     and Params.clientInfo.version.HasValue then
     clientInfoVersion := ' ' + Params.clientInfo.version.Value
   else
     clientInfoVersion := '';
 
   DoLog(kStatusPrefix+'Server: ' + {$INCLUDE %DATE%});
-  DoLog(kStatusPrefix+'Client: ' + Params.clientInfo.name + clientInfoVersion);
+  if Assigned(Params.clientInfo) then
+    DoLog(kStatusPrefix+'Client: ' + Params.clientInfo.name + clientInfoVersion)
+  else
+    DoLog(kStatusPrefix+'Client: <unknown>');
 
   DoLog(kStatusPrefix+'FPCPath: ' + CodeToolsOptions.FPCPath);
   DoLog(kStatusPrefix+'FPCSrcDir: ' + CodeToolsOptions.FPCSrcDir);