diff --git a/crates/nu-lsp/src/diagnostics.rs b/crates/nu-lsp/src/diagnostics.rs
index a6126e02c0..78da896266 100644
--- a/crates/nu-lsp/src/diagnostics.rs
+++ b/crates/nu-lsp/src/diagnostics.rs
@@ -73,7 +73,7 @@ mod tests {
     use lsp_types::Url;
     use nu_test_support::fs::fixtures;
 
-    use crate::tests::{initialize_language_server, open, update};
+    use crate::tests::{initialize_language_server, open_unchecked, update};
 
     #[test]
     fn publish_diagnostics_variable_does_not_exists() {
@@ -85,7 +85,7 @@ mod tests {
         script.push("var.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        let notification = open(&client_connection, script.clone());
+        let notification = open_unchecked(&client_connection, script.clone());
 
         assert_json_eq!(
             notification,
@@ -116,7 +116,7 @@ mod tests {
         script.push("var.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
         let notification = update(
             &client_connection,
             script.clone(),
diff --git a/crates/nu-lsp/src/lib.rs b/crates/nu-lsp/src/lib.rs
index 51a60a7e4a..70c49371c8 100644
--- a/crates/nu-lsp/src/lib.rs
+++ b/crates/nu-lsp/src/lib.rs
@@ -180,7 +180,7 @@ impl LanguageServer {
     }
 
     fn span_to_range(span: &Span, rope_of_file: &Rope, offset: usize) -> lsp_types::Range {
-        let line = rope_of_file.char_to_line(span.start - offset);
+        let line = rope_of_file.byte_to_line(span.start - offset);
         let character = span.start - offset - rope_of_file.line_to_char(line);
 
         let start = lsp_types::Position {
@@ -188,7 +188,7 @@ impl LanguageServer {
             character: character as u32,
         };
 
-        let line = rope_of_file.char_to_line(span.end - offset);
+        let line = rope_of_file.byte_to_line(span.end - offset);
         let character = span.end - offset - rope_of_file.line_to_char(line);
 
         let end = lsp_types::Position {
@@ -704,8 +704,16 @@ mod tests {
         assert_json_eq!(result, serde_json::json!(null));
     }
 
-    pub fn open(client_connection: &Connection, uri: Url) -> lsp_server::Notification {
-        let text = std::fs::read_to_string(uri.to_file_path().unwrap()).unwrap();
+    pub fn open_unchecked(client_connection: &Connection, uri: Url) -> lsp_server::Notification {
+        open(client_connection, uri).unwrap()
+    }
+
+    pub fn open(
+        client_connection: &Connection,
+        uri: Url,
+    ) -> Result<lsp_server::Notification, String> {
+        let text =
+            std::fs::read_to_string(uri.to_file_path().unwrap()).map_err(|e| e.to_string())?;
 
         client_connection
             .sender
@@ -721,17 +729,17 @@ mod tests {
                 })
                 .unwrap(),
             }))
-            .unwrap();
+            .map_err(|e| e.to_string())?;
 
         let notification = client_connection
             .receiver
             .recv_timeout(Duration::from_secs(2))
-            .unwrap();
+            .map_err(|e| e.to_string())?;
 
         if let Message::Notification(n) = notification {
-            n
+            Ok(n)
         } else {
-            panic!();
+            Err(String::from("Did not receive a notification from server"))
         }
     }
 
@@ -813,7 +821,7 @@ mod tests {
         script.push("var.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = goto_definition(&client_connection, script.clone(), 2, 12);
         let result = if let Message::Response(response) = resp {
@@ -844,7 +852,7 @@ mod tests {
         script.push("command.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = goto_definition(&client_connection, script.clone(), 4, 1);
         let result = if let Message::Response(response) = resp {
@@ -875,7 +883,7 @@ mod tests {
         script.push("command.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = goto_definition(&client_connection, script.clone(), 1, 14);
         let result = if let Message::Response(response) = resp {
@@ -929,7 +937,7 @@ mod tests {
         script.push("var.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = hover(&client_connection, script.clone(), 2, 0);
         let result = if let Message::Response(response) = resp {
@@ -956,7 +964,7 @@ mod tests {
         script.push("command.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = hover(&client_connection, script.clone(), 3, 0);
         let result = if let Message::Response(response) = resp {
@@ -1011,7 +1019,7 @@ mod tests {
         script.push("var.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = complete(&client_connection, script, 2, 9);
         let result = if let Message::Response(response) = resp {
@@ -1047,7 +1055,7 @@ mod tests {
         script.push("command.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = complete(&client_connection, script, 0, 8);
         let result = if let Message::Response(response) = resp {
@@ -1073,4 +1081,41 @@ mod tests {
             ])
         );
     }
+
+    #[test]
+    fn complete_command_with_utf_line() {
+        let (client_connection, _recv) = initialize_language_server();
+
+        let mut script = fixtures();
+        script.push("lsp");
+        script.push("completion");
+        script.push("utf_pipeline.nu");
+        let script = Url::from_file_path(script).unwrap();
+
+        open_unchecked(&client_connection, script.clone());
+
+        let resp = complete(&client_connection, script, 0, 14);
+        let result = if let Message::Response(response) = resp {
+            response.result
+        } else {
+            panic!()
+        };
+
+        assert_json_eq!(
+            result,
+            serde_json::json!([
+               {
+                  "label": "str trim",
+                  "detail": "Trim whitespace or specific character.",
+                  "textEdit": {
+                     "range": {
+                        "start": { "line": 0, "character": 9 },
+                        "end": { "line": 0, "character": 14 },
+                     },
+                     "newText": "str trim"
+                  }
+               }
+            ])
+        );
+    }
 }
diff --git a/crates/nu-lsp/src/notification.rs b/crates/nu-lsp/src/notification.rs
index 085baebcbd..8bfab92664 100644
--- a/crates/nu-lsp/src/notification.rs
+++ b/crates/nu-lsp/src/notification.rs
@@ -95,7 +95,7 @@ mod tests {
     use lsp_types::{Range, Url};
     use nu_test_support::fs::fixtures;
 
-    use crate::tests::{hover, initialize_language_server, open, update};
+    use crate::tests::{hover, initialize_language_server, open, open_unchecked, update};
 
     #[test]
     fn hover_correct_documentation_on_let() {
@@ -107,7 +107,7 @@ mod tests {
         script.push("var.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
 
         let resp = hover(&client_connection, script.clone(), 0, 0);
         let result = if let Message::Response(response) = resp {
@@ -137,7 +137,7 @@ mod tests {
         script.push("command.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
         update(
             &client_connection,
             script.clone(),
@@ -178,7 +178,7 @@ hello"#,
         script.push("command.nu");
         let script = Url::from_file_path(script).unwrap();
 
-        open(&client_connection, script.clone());
+        open_unchecked(&client_connection, script.clone());
         update(
             &client_connection,
             script.clone(),
@@ -212,4 +212,19 @@ hello"#,
             })
         );
     }
+
+    #[test]
+    fn open_document_with_utf_char() {
+        let (client_connection, _recv) = initialize_language_server();
+
+        let mut script = fixtures();
+        script.push("lsp");
+        script.push("notifications");
+        script.push("issue_11522.nu");
+        let script = Url::from_file_path(script).unwrap();
+
+        let result = open(&client_connection, script);
+
+        assert_eq!(result.map(|_| ()), Ok(()))
+    }
 }
diff --git a/tests/fixtures/lsp/completion/utf_pipeline.nu b/tests/fixtures/lsp/completion/utf_pipeline.nu
new file mode 100644
index 0000000000..5a5a7ce4d2
--- /dev/null
+++ b/tests/fixtures/lsp/completion/utf_pipeline.nu
@@ -0,0 +1 @@
+" è " | str t
diff --git a/tests/fixtures/lsp/notifications/issue_11522.nu b/tests/fixtures/lsp/notifications/issue_11522.nu
new file mode 100644
index 0000000000..6bc1b59844
--- /dev/null
+++ b/tests/fixtures/lsp/notifications/issue_11522.nu
@@ -0,0 +1,6 @@
+#!/usr/bin/env nu
+
+# Important to reproduce the crash
+# use a non ascii char somewhere in comments: è
+
+[a b c d] | filter {