2588960 - 'Error loading database connector...' when refreshing a report in Crystal Reports for Enterprise

SAP Knowledge Base Article - Public

2588960 - 'Error loading database connector...' when refreshing a report in Crystal Reports for Enterprise

Symptom

  • Fail to refresh a report.
  • Was able to refresh the report before.
  • When refreshing a report in Crystal Reports for Enterprise, it fails with the error:
       
       "The following error has occured while trying to retreive the data:
       
        Error loading database connector. The class 'com.crystaldecisions.reports.queryengine.drivermpl.DriverLoader'
        could not be accessed.
     
        Please check with your System Administrator that the data source is correctly configured."
      
        Crystal Reports for Enterprise - Refresh Error.png

Environment

  • SAP Crystal Reports for Enterprise 4.0
  • SAP Crystal Reports for Enterprise 4.1
  • SAP Crystal Reports for Enterprise 4.2

Reproducing the Issue

  1. In Crystal Reports for Enterprise, open an existing report.
  2. When refreshing the report, it fails with the error:
     
    "Error loading database connector. The class 'com.crystaldecisions.reports.queryengine.drivermpl.DriverLoader'
      could not be accessed."

Cause

  • The report was created in Crystal Reports for Enterprise, but was modified in Crystal Reports designer, then when opening the modified report it generate the error because by opening and saving the report in Crystal Reports designer, it broke the database connectivity of the report.
        
  • When opening a report created in Crystal Reports for Enterprise, in Crystal Reports designer, it shows a warning stating this report was designed in Crystal Reports for Enterprise. The warning was ignored, and the report modified, and by doing so, it breaks the database connectivity.
      
      Crystal Reports for Enterprise - Warning.png

Resolution

  • To be able to refresh the report, set the data source location of the report to point to the database required for the report.
        
    1. In Crystal Reports for Enterprise, open the report on which you are experiencing the error.
       
    2. Under the menu "Data", select "Set Data Source Location..."
       
    3. Under the Target Data Source, connect to the data source the report was based off.
         
    4. Under Current Data Source, select the current incorrect data source, and then click the "Map" button under "Target Data Source" to point the report to the correct data source.
         
    5. Once complete, click "Done", and save the report.
         
      You will then be able to successfully refresh the report.

Keywords

CR4E, CRFE, CR for Ent, CR for Enterprise , KBA , BI-RA-CRE , Crystal Reports for Enterprise , Problem

Product

SAP Crystal Reports 2011 ; SAP Crystal Reports 2013 ; SAP Crystal Reports 2016