diff --git a/zhang-cli/src/opendal.rs b/zhang-cli/src/opendal.rs
index 5d8ea4c8..fcc14839 100644
--- a/zhang-cli/src/opendal.rs
+++ b/zhang-cli/src/opendal.rs
@@ -6,7 +6,7 @@ use async_recursion::async_recursion;
 use beancount::Beancount;
 use log::{debug, error, info};
 use opendal::services::{Fs, Webdav};
-use opendal::{ErrorKind, Operator};
+use opendal::Operator;
 use zhang_ast::{Directive, Include, SpanInfo, Spanned, ZhangString};
 use zhang_core::data_source::{DataSource, LoadResult};
 use zhang_core::data_type::text::parser::parse as zhang_parse;
@@ -77,12 +77,8 @@ impl DataSource for OpendalDataSource {
         match result {
             Ok(data) => Ok(data),
             Err(err) => {
-                if err.kind() == ErrorKind::NotFound {
-                    Ok(Vec::new())
-                } else {
-                    error!("cannot get content from {}: {}", &path, &err);
-                    Ok(Vec::new())
-                }
+                error!("cannot get content from {}: {}", &path, &err);
+                Err(ZhangError::CustomError("error on getting file content"))
             }
         }
     }
diff --git a/zhang-core/src/error.rs b/zhang-core/src/error.rs
index f3d800f9..843c73a3 100644
--- a/zhang-core/src/error.rs
+++ b/zhang-core/src/error.rs
@@ -32,6 +32,9 @@ pub enum ZhangError {
 
     #[error("invalid content encoding: {0}")]
     ContentEncodingError(#[from] std::string::FromUtf8Error),
+
+    #[error("custom error: {0}")]
+    CustomError(&'static str),
 }
 
 pub trait IoErrorIntoZhangError<T> {
diff --git a/zhang-server/src/routes/document.rs b/zhang-server/src/routes/document.rs
index ab9d6bca..34cb0017 100644
--- a/zhang-server/src/routes/document.rs
+++ b/zhang-server/src/routes/document.rs
@@ -20,12 +20,12 @@ pub async fn download_document(ledger: State<Arc<RwLock<Ledger>>>, path: Path<(S
     let filename = String::from_utf8(BASE64_STANDARD.decode(&encoded_file_path).unwrap()).unwrap();
     let ledger = ledger.read().await;
     let entry = &ledger.entry.0;
-    let full_path = entry.join(filename);
-    let striped_path = full_path.strip_prefix(entry).unwrap();
-    let file_name = striped_path.file_name().unwrap().to_string_lossy().to_string();
+    let full_path = dbg!(entry.join(filename));
+    let striped_path = dbg!(full_path.strip_prefix(entry).unwrap());
+    let file_name = dbg!(striped_path.file_name().unwrap().to_string_lossy().to_string());
     let content = cacheable_data(&encoded_file_path, async {
         info!("loading file [{:?}] data from remote...", &striped_path);
-        ledger.data_source.async_get(striped_path.to_string_lossy().to_string()).await
+        ledger.data_source.async_get(dbg!(striped_path.to_string_lossy().to_string())).await
     })
     .await
     .expect("cannot get file data");