Errors in the OLAP Storage Engine: The attribute key cannot be found

When you try to process a cube using SQL Server Business Intelligence Development studio or SQL Server Management Studio, you may receive the following error:

Errors in the OLAP storage engine: The attribute key cannot be found: Table: TableName, Column: ColumnName1, Value: Value1.

Resolution
This issue occurs because a fact table for a cube has one or more records that contain an attribute key and this attribute key does not exist in the corresponding dimension table.

1. Try to process the relevant dimension and then try to process the cube again.
2. Try to correct the data of the fact table by using a UPDATE command for the table, column and value given in the error message.
3. Try to add a record to the dimension table for the given table and value.
4. Ignore the error.  If you want to process the cube without correcting the data, you can set the error configuration for the process operation to ignore the error using the steps below. You should only do this as a temporary workaround while you fix the underlying data.
   1. In the Process Database – DatabaseName dialog box or the Process Cube – CubeName dialog box, click Change Settings. 
   2.  In the Change Settings dialog box, click the Dimension key errors tab.
   3. Click Use custom error configuration.
   4. In the Key not found list, change the default value from Report and continue to Ignore error.
   5. Click Ignore errors count.
   6. Click OK to close the Change Settings dialog box.
   7. Click OK to process the database or the cube.