CRM 2016: The attribute with AttributeId = 'guid' was not found in the MetadataCache.

During the export of an unmanged solution I always received the following error message from my CRM 2016 SP1 OnPremise development system:

The attribute with AttributeId = '023bda49-9dfa-401e-b348-9374a4141186' was not found in the MetadataCache.

Then I tried to remember what I did since the last solution version.
=> Yes, there was a field that I deleted, because the customer does not need it anymore.

Because I am working on-premise it was easy to check the database for the specific attribute.
First, I searched in the attribute table:

SELECT [AttributeId]
  FROM [Dev_MSCRM].[MetadataSchema].[Attribute]
  where [AttributeId] = '023bda49-9dfa-401e-b348-9374a4141186'

=> result was nothing

I concluded CRM deleted the field in this table but missed to remove the attribute from our customer solution.

Next thing was to check the solutioncomponent table:

SELECT [ModifiedOn]
      ,[CreatedBy]
      ,[ObjectId]
      ,[IsMetadata]
      ,[ModifiedBy]
      ,[SolutionId]
      ,[SolutionComponentId]
      ,[CreatedOn]
      ,[VersionNumber]
      ,[ComponentType]
      ,[CreatedOnBehalfBy]
      ,[ModifiedOnBehalfBy]
      ,[RootComponentBehavior]
      ,[RootSolutionComponentId]
  FROM [Dev_MSCRM].[dbo].[SolutionComponentBase]
  where ObjectId = '023bda49-9dfa-401e-b348-9374a4141186'

=> There we go! There is still an entry where it should not be :(

Now I backed up this record from this table and deleted this record from the solutioncomponentbase table:

DELETE FROM [dbo].[SolutionComponentBase]
      WHERE ObjectId = '023bda49-9dfa-401e-b348-9374a4141186'

Next time I tried to export the solution it worked just perfectly.
Problem solved!