Subscriptions cannot be edited or new created

All the existing subscriptions still work, however they cannot be edited. No new subscriptions can be setup.

Error from the log when trying to validate the subscription data query:

extensionfactory!ReportServer_0-1!1c08!01/07/2020-16:16:28:: e ERROR: Exception caught instantiating DAX report server extension: Microsoft.ReportingServices.Diagnostics.Utilities.ServerConfigurationErrorException: The report server has encountered a configuration error. ---> System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.ReportingServices.Cloud.DataExtensions' or one of its dependencies. The system cannot find the file specified..