diff --git a/src/services/DhService.ts b/src/services/DhService.ts
index d4d5138b..6b06e95e 100644
--- a/src/services/DhService.ts
+++ b/src/services/DhService.ts
@@ -263,18 +263,25 @@ export abstract class DhService<TDH, TClient>
 
       if (line != null) {
         // If selectionOnly is true, the line number in the error will be
-        // relative to the selection
-        const offsetLine = selectionOnly
-          ? line + editor.selection.start.line - 1
-          : line - 1;
+        // relative to the selection (Python line numbers are 1 based. vscode
+        // line numbers are zero based.)
+        const fileLine =
+          (selectionOnly ? line + editor.selection.start.line : line) - 1;
 
-        const lineLength = editor.document.lineAt(offsetLine).text.length;
+        // There seems to be an error for certain Python versions where line
+        // numbers are shown as -1. In such cases, we'll just mark the first
+        // token on the first line to at least flag the file as having an error.
+        const startLine = Math.max(0, fileLine);
+
+        // Zero length will flag a token instead of a line
+        const lineLength =
+          fileLine < 0 ? 0 : editor.document.lineAt(fileLine).text.length;
 
         // Diagnostic representing the line of code that produced the server error
         const diagnostic: vscode.Diagnostic = {
           message: value == null ? error : `${value}\n${error}`,
           severity: vscode.DiagnosticSeverity.Error,
-          range: new vscode.Range(offsetLine, 0, offsetLine, lineLength),
+          range: new vscode.Range(startLine, 0, startLine, lineLength),
           source: 'deephaven',
         };
 
diff --git a/src/util/errorUtils.ts b/src/util/errorUtils.ts
index 456fbf9d..07d98de5 100644
--- a/src/util/errorUtils.ts
+++ b/src/util/errorUtils.ts
@@ -30,7 +30,7 @@ export function parseServerError(error: string): ParsedError {
 
     const [key, value] = line.split(':');
 
-    if (key && value) {
+    if (key.length) {
       // Once we hit the Traceback, accumulate remaining lines
       if (key === 'Traceback (most recent call last)') {
         errorDetails.traceback = [value, ...lines].join('\n');
@@ -42,5 +42,17 @@ export function parseServerError(error: string): ParsedError {
     }
   }
 
+  // If top-level error isn't associated with File: "<string>", look for the
+  // first match in the traceback.
+  if (errorDetails.file !== '<string>' && errorDetails.traceback != null) {
+    const fileStringRegEx = /\s+File "<string>", line (\d+), in <module>/;
+    const [, lineNumberStr] =
+      fileStringRegEx.exec(errorDetails.traceback) ?? [];
+
+    if (lineNumberStr != null) {
+      errorDetails.line = Number(lineNumberStr);
+    }
+  }
+
   return errorDetails;
 }