Web Console is inaccessible with "FATAL SolarWinds.Orion.Licensing.BusinessLayer.LicensingBusinessLayerPlugin - Unhandled Exception caught in plugin startup" error

Users cannot access the web console, showing "Server Error in '/' Application", after applying a new license or doing a migration while reusing an old server.

Upon checking the Licensing.BusinessLayer.log, the following error is seen.

2025-11-04 16:29:39,989 [18] DEBUG SolarWinds.Orion.Licensing.LocalLeases.LeaseStoreFile - Checking existence of lease store at 'C:\Program Files\SolarWinds\Orion\lease.dat'. Exists: False.
2025-11-04 16:29:39,989 [18] DEBUG SolarWinds.Orion.Licensing.LocalLeases.LeaseStoreFile - Checking existence of lease store at 'C:\ProgramData\SolarWinds\lease.dat'. Exists: True.
2025-11-04 16:29:39,989 [18] DEBUG SolarWinds.Orion.Licensing.LocalLeases.LeaseStoreFile - READING from lease store file at 'C:\ProgramData\SolarWinds\lease.dat'.
2025-11-04 16:29:40,275 [18] ERROR SolarWinds.Orion.Feature.Service.Mapping.FeatureMapper - License Mismatch
2025-11-04 16:29:40,275 [18] FATAL SolarWinds.Orion.Licensing.BusinessLayer.LicenseServerMode - DoStartBeforeSwis failed
Castle.MicroKernel.ComponentActivator.ComponentActivatorException: ComponentActivator: could not instantiate SolarWinds.Orion.Feature.Service.Mapping.FeatureMapper ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidOperationException: License Mismatch
   at SolarWinds.Orion.Feature.Service.Mapping.FeatureMapper..ctor(ILicenseInfoWrapper wrapper)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
   at System.Reflection.RuntimeConstructorInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Castle.MicroKernel.ComponentActivator.DefaultComponentActivator.FastCreateInstance(Type implType, Object[] arguments, ConstructorCandidate constructor)
   at Castle.MicroKernel.ComponentActivator.DefaultComponentActivator.CreateInstanceCore(ConstructorCandidate constructor, Object[] arguments, Type implType)
   --- End of inner exception stack trace ---

Corrupted lease.dat and/or license.dat files that don't match the database. Usually caused by a reused server or a bad migration.

1. Stop All SolarWinds Service Manager Services

   1. Open SolarWinds Service Manager and click the "Stop Everything" button.

2. Locate the License Files

   1. Navigate to:
      C:\ProgramData\SolarWinds\
   2. Find the files named:
      1. lease.dat
      2. license.dat

3. Move the Files to a Backup Location

   1. Copy or move these files to a different folder, e.g. Downloads, Backup, or another safe location.

4. Restart All SolarWinds Services

   1. Using SolarWinds Service Manager, start all previously stopped services.
   2. Wait about 1-3 minutes to give services a chance to start up

5. Access the Web Console

   1. Open up the Web console to confirm functionality.

6. Reapply Licenses

   1. If necessary, reapply the proper license to the system.