The following error is written to the the Miner Event log when Workflow Manager is started from custom web service code:
012-07-12 06:08:50,113  ERROR - mmPxBaseUI.dll::PxApplication.Startup Failed to set data for 'Provider' Error at line: 1027 - Build: 10.2.7217 at Miner.Interop.Process.PxApplicationClass.Startup(IMMPxLogin pPxLogin) at Nisource.WebServices.CreateWorkRequest.LoadWFM(StringBuilder designXML, Int32& designID, Int32& workRequestID) in C:\Telvent_Code\Maximo\Nisource.WebServices\CreateWorkRequest.asmx.cs:line 212 at Nisource.WebServices.CreateWorkRequest.Submit(String message) in C:\Telvent_Code\Maximo\Nisource.WebServices\CreateWorkRequest.asmx.cs:line 98
Starting Workflow Manager requires access to the registry. When running the web service from IIS, it is not able to access the registry if the permissions are not correct. This will cause the error shown above.
To view the access errors, Process Monitor can be run on the w3wp.exe process to capture the registry access errors. They will show up as ACCESS DENIED in the Result column of Process Monitor.
Once the access issues have been identified, they can be changed by using regedit. Start regedit and browse to the registry entry that needs access changes. Right click on the entry and select Security. Often this requires adding the Application Pool that the application is using. This can be found in IIS Manager by select the application, then selecting Basic Settings in the Actions panel.