Siemens Industry Online Support
Siemens AG
Entry type: FAQ Entry ID: 109739926, Entry date: 10/04/2016

Why is it not possible to start the TIA Portal Multiuser Service after installation?

  • Entry
  • Associated product(s)
In some cases the service does not start because of a logon error.

If you cannot start the TIA Portal Multiuser Service because of the error described in the introduction, the causes are as listed below:

  • The password for the TIA Portal Multiuser has been changed or is no longer valid.
  • The "Log on as a service policy" rights have been denied for the specified user account.

First of all, in the TIA Portal Multiuser Service - Logon you delete the password and restart the server.

If you still cannot start the MU Service or if, after starting the server, the behavior described above repeats itself after a number of hours or days, then probably the user rights assignment has been interrupted by the system. In this case you have to restore the right of the user to logon as a service policy.

The procedure below is for MS Windows 7 Enterprise (Service Pack 1).

Check that the security setting "NT SERVICE\ALL SERVICES" has been assigned for logon with the local policies. These settings are to be found in MS Windows under "Local Security Policy". For this you proceed as follows:

  1. In MS Windows you open the "Run" dialog field via "Start > Run" or via the key combination "Windows Logo + R".
  2. Enter the command "secpol.msc" and click OK.
  3. Acknowledge the message that follows with "Yes. The "Local Security Policy" dialog opens.
  4. Navigate to "Security Settings > Local Policies > User Rights Assignment".
  5. In the right window you check the two policies below:
  • The "Log on as a service policy" policy must have the security setting "NT SERVICE\ALL SERVICES".
  • The "Deny logon as a service policy" policy must not have the security setting "NT SERVICE\ALL SERVICES".

Fig. 1

If you have to configure or change the policies, you right-click "Log on as a service policy", for example, and select "Properties" in the pop-up menu. In the "Properties" dialog you see the functions "Add user or group..." and "Remove".

You need administrator rights for the procedure described above.

Further Information
More information is available on the MS Windows Support pages under How To Troubleshoot Service Startup Permissions in Windows.

Creation Environment
Figure 1 was created in MS Windows 7 SP1 Enterprise.

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit