[Connection Issues] A message that says "Unstable network connection. If the issue continues, please contact Customer Service" appears.
Check the following if you receive a message that reads "Unstable network connection. If the issue continues, please contact Customer Service".

1. Check your network connection.

2. Go to Internet Options > Security > Trusted sites > Sites and try the following.
1) Uncheck "Require server verification (https:) for all sites in this zone".
2) Add "*.kakao.com" as a trusted website.
3) If the same issue occurs after trying no. 2 above, delete URLs related to "cmail.kakao.com".

3. Go to Internet Options > General > Browsing history > Delete... > Check "Preserve Favorites website data", "Temporary Internet files and website files", "Cookies and website data" and delete.

4. Go to Internet Options > Security > Click "Reset all zones to default level" and press "OK".

5. Install Daum Cleaner > Manage PC > Press the "Toolbar/IE add-ons" tab and delete anything that looks suspicious.

6. Disable any suspicious programs.
▶ [Internet Explorer] users
Go to Settings > Manage add-ons > Check the ActiveX that was loaded, and change all modules other than those provided by Daum Communications Corp., Kakao Corp., Adobe Systems Incorporated, Microsoft Corporation, Sun Microsystems, Inc. and Shockwave Flash Object to do not use.
▶ [Chrome] users
Go to More tools > Extensions > disable suspicious programs.

7. Go to Control Panel > Uninstall a program > Uninstall suspicious programs.

8. Delete Chrome extensions.
Ex) Allow-Control-Allow-Origin: *