To resolve the issue, consider the following options:
- Upgrade Sitecore XP instance to Sitecore XP 9.0.2 or later in order to use the later version of the Azure Cognitive Search REST API.
- Download and install the hotfix compatible with the affected product version found on this page:
Be aware that the hotfixes were built for specific Sitecore XP versions, and must not be installed on other Sitecore XP versions or in combination with other hotfixes. In case any other hotfixes have already been installed on a certain Sitecore XP instance, send a request for a compatibility check to Sitecore Support.
Note that the ZIP file contents need to be extracted to locate installation instructions and related files inside. The hotfixes must be installed on a CM instance and then synced with other instances using standard development practices.