diff --git a/lua/avante/floating_window.lua b/lua/avante/floating_window.lua
index edbc271..651a3c2 100644
--- a/lua/avante/floating_window.lua
+++ b/lua/avante/floating_window.lua
@@ -91,7 +91,12 @@ function FloatingWindow.from_split_win(split_winid, opts)
     api.nvim_create_autocmd("WinResized", {
       group = floating_win.augroup,
       callback = function()
-        if not api.nvim_win_is_valid(split_winid) or not api.nvim_win_is_valid(winid) then
+        if
+          not split_winid
+          or not winid
+          or not api.nvim_win_is_valid(split_winid)
+          or not api.nvim_win_is_valid(winid)
+        then
           return
         end
 
@@ -113,7 +118,12 @@ function FloatingWindow.from_split_win(split_winid, opts)
     api.nvim_create_autocmd("WinResized", {
       group = floating_win.augroup,
       callback = function()
-        if not api.nvim_win_is_valid(split_winid) or not api.nvim_win_is_valid(winid) then
+        if
+          not split_winid
+          or not winid
+          or not api.nvim_win_is_valid(split_winid)
+          or not api.nvim_win_is_valid(winid)
+        then
           return
         end
 
diff --git a/lua/avante/sidebar.lua b/lua/avante/sidebar.lua
index c3ab83f..9f782ae 100644
--- a/lua/avante/sidebar.lua
+++ b/lua/avante/sidebar.lua
@@ -106,7 +106,7 @@ function Sidebar:close()
       comp:unmount()
     end
   end
-  if self.code ~= nil and api.nvim_win_is_valid(self.code.winid) then
+  if self.code and self.code.winid and api.nvim_win_is_valid(self.code.winid) then
     fn.win_gotoid(self.code.winid)
   end
 
@@ -589,7 +589,7 @@ function Sidebar:on_mount()
   api.nvim_create_autocmd("User", {
     pattern = VIEW_BUFFER_UPDATED_PATTERN,
     callback = function()
-      if self.result == nil then
+      if not self.result or not self.result.bufnr or not api.nvim_buf_is_valid(self.result.bufnr) then
         return
       end
       codeblocks = parse_codeblocks(self.result.bufnr)
@@ -775,8 +775,9 @@ function Sidebar:refresh_winids()
     else
       current_idx = current_idx + 1
     end
-    if api.nvim_win_is_valid(winids[current_idx]) then
-      api.nvim_set_current_win(winids[current_idx])
+    local winid = winids[current_idx]
+    if winid and api.nvim_win_is_valid(winid) then
+      api.nvim_set_current_win(winid)
     end
   end
 
@@ -788,8 +789,9 @@ function Sidebar:refresh_winids()
     else
       current_idx = current_idx - 1
     end
-    if api.nvim_win_is_valid(winids[current_idx]) then
-      api.nvim_set_current_win(winids[current_idx])
+    local winid = winids[current_idx]
+    if winid and api.nvim_win_is_valid(winid) then
+      api.nvim_set_current_win(winid)
     end
   end
 
@@ -1265,6 +1267,9 @@ function Sidebar:create_input()
   end)
 
   local function on_submit()
+    if not self.input or not self.input.bufnr or not api.nvim_buf_is_valid(self.input.bufnr) then
+      return
+    end
     local lines = api.nvim_buf_get_lines(self.input.bufnr, 0, -1, false)
     local request = table.concat(lines, "\n")
     if request == "" then