After an IOP (Insights On-Premises) upgrade, all reports return an error
In rare scenarios the upgrade might cause cleanup of indexed data and rebuild is necessary to create the available data sets.
Please go to the data model settings and rebuild your data sets accelaration.
To reach the data model settings page, type your Insights URL and add manager/search/data_model_manager
For example: http://servername.domain.com:8000/en-US and to it add manager/search/data_model_manager
Once you reach the settings page, please click on rebuild for each report's data set.
The rebuild takes few minutes, check the Insights reports after 30 minutes.