Update app.py

app.py

@@ -431,6 +431,8 @@ if uploaded_file_paths is not None:
     st.session_state.file_names = file_names
 
 file_names = st.session_state.file_names
+if not file_names:
+    file_names = []
     
 if len(file_names) == 0:
     st.text("Upload file(s) to enable analysis")
@@ -566,6 +568,9 @@ if currFile is None and len(st.session_state.results) > 0 and len(st.session_sta
     st.write("Select a file to view from the sidebar")
 try:
     st.session_state.resetResult = False
+    if currFile is None:
+        st.info("Select a file from the sidebar to view results.")
+        raise ValueError("No file selected")
     currFileIndex = file_names.index(currFile)
     currPlainName = currFile.split('.')[0]
     if len(st.session_state.results) > currFileIndex and len(st.session_state.summaries) > currFileIndex and len(st.session_state.results[currFileIndex]) > 0: