Debugging cannot be started on the Web server. An authentication error occurred while communicating with the Web server. solution!

Step 1: To disable the loop check, follow these steps:

1. Open the Registry Editor (Click Start, click Run, type regedit, and then click OK ).

2. In the Registry Editor, find and click the following registry key: HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ LSA

3. Right-click LSA, point to new, and click DWORD Value.

4. Type disableloopbackcheck and press Enter.

5. Right-click disableloopbackcheck and click Modify.

6. In the value data box, type 1 and click OK.

7. Exit Registry Editor and restart the computer. (Do not restart the computer)
Step 2:

To specify the host name, you must map it to the loopback address and connect it to the Web site. follow these steps:

1. Open the Registry Editor (Click Start, click Run, type regedit, and then click OK ). .

2. In the Registry Editor, find and click the following registry key: HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ LSA \ msv1_0

3. Right-click msv1_0, point to new, and then click multi-string value.

4. Type backconnectionhostnames and then press Enter.

5. Right-click backconnectionhostnames and click Modify.

6. In the value data box, type the host name or host name as the name of the local computer where the site is located, and then click OK.

7. Exit the Registry Editor and restart the IISADMIN service.