Fixing the Error in the Communication/Transmission of Diablo 3

There was a communication/transmission error. Please restart. If the problem persists, please contact customer service.

Players who participated in the Diablo III beta may experience this error when installing the game. If you participated in the beta and receive this error when you attempt to install, completely uninstall the beta client and follow the troubleshooting steps below.

Agent
Issues with the Agent helper program may prevent Diablo III from installing or updating properly. If you notice your installation hanging, or if you receive errors specific to Agent, try the following steps:

Windows

1. Stop the installation process if it’s still running.
2. Wait for at least one minute. Ensure that Agent.exe no longer appears in the Processes tab of your Task Manager.
3. Restart the installation.

If that does not resolve the issue, delete the C:\ProgramData\Battle.net folder and try the installation again. The launcher will automatically rebuild this folder. If you cannot locate this folder, try these steps:

1. Click Start

2. Click Control Panel

3. If you are in Classic View: Select Folder Options > Click the View tab > In Advanced Settings under Hidden files and folders, select Show hidden files, folders, and drives. > Click OK.
Or
If you are in Category View: Select Appearance and Personalization > In the Folder Options section, select Show hidden files and folders. This will bring up the Folder Options window. > Click on the View tab. > In the Advanced Settings section under Hidden files and folders, select Show hidden files, folders, and drives. > Click OK.

4. Try again to navigate to the proper folder:

Windows Vista/7: C:\ProgramData\Battle.net

Windows XP: Documents and Settings\All Users\Application Data

5. Delete the folder, then reattempt the installation.

Mac
1. Stop the installation process if it’s still running.
2. Wait at least one minute. Ensure that Agent no longer appears in your Activity Monitor. For information on how to access your Activity Monitor, see our Background Applications support article.
3. Restart the installation.

If that does not resolve the issue, delete the /Users/Shared/Battle.net folder and try the installation again. The launcher will automatically rebuild this folder.