Microsoft recently released an update to Windows 10 called the April 2018 (version 1803) release. With this update Microsoft is no longer supporting Server Message Block version 1 (SMBv1). Server Message Block is a protocol that allows files, printer, and other network resources to be shared on a computer network. If version SMBv2 and/or SMBv3 have been disabled on your workstations and server then errors may occur when attempting to connect to SQL databases after applying this update.
Warning: Important this email contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs.
Symptoms:
1. Windows 10 computer has recently updated.
2. Computer is unable to connect to a SQL database, but can connect to an access database (if applicable).
Troubleshooting:
1. On the affected computer press the Windows button and type Command. Select Command Prompt from the available results.
2. In the command prompt window type winver. Press Enter.
3. Verify that the version displayed is 1803.
4. On your server, verify that SMBv2 and SMBv3 are enabled and that SMBv1 is disabled. Follow the steps below to make this verification.
a. Open the Registry Editor by pressing the Windows button and typing Regedit. Select Regedit from the resulting list.
b. Locate the following hives:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters]
If there is an entry for SMB2 and the value is 0 then SMBv2 is disabled. Right click the entry, select Modify. Replace the 0 with 1. Click OK. If you do not have an SMB2 entry check for SMB3.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters]
If there is an entry for SMB3 and the value is 0 then SMBv3 is disabled. Right click the entry, select Modify. Replace the 0 with 1. Click OK. If you do not have an SMB3 entry check for SMB1.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters]
If there is an entry for SMB1 and the value is 1 then SMBv1 is enabled. Right click the entry, select Modify. Replace the 1 with 0. Click OK.
6. Restart the server.
7. Should you have issues connecting after the server has restarted you may need to make the same registry changes on all computers and reboot.
8. If you do not find any SMB entries please refer to the following documentation from Microsoft to learn how to detect, disable, and enable SMB versions.
https://support.microsoft.com/en-us/help/2696547/how-to-detect-enable-and-disable-smbv1-smbv2-and-smbv3-in-windows-and