Looking at the log error information, I think the error is because of a driver not being updated or referenced correctly. Here are a few things I would check:
1. [This ](https://community.denodo.com/docs/html/browse/7.0/platform/migration/export_the_metadata_of_the_current_installation) guide was followed for exporting the metadata.
2. Making sure the drivers and metadata was imported correctly as referenced [here](https://community.denodo.com/docs/html/browse/7.0/platform/migration/import_the_metadata_to_the_new_installation).
3. If the above was done succesfully, go to your data source and look at the "Driver Class Path" under the *Connection* tab. Make sure that the Driver Class Path is not the location of your previous installation db driver, but the new updated location path after the migration. In 7.0, you can optionally use a driver alias folder for the Driver Class Path, for example, 'db2-9' instead of listing the updated driver path in its entirety.
Hope this helps!