ASP.NET Rendering Host might render an error in Experience Editor when the personalization action for the component variant is set to Hide. This happens after saving the page where the component with personalization is set.
Saving the page while the hidden component is selected causes Experience Editor to fail. Experience Editor will not be available until the personalization settings for the component have been reset. After that, the page must be recovered through the Layout Details dialog. The issue does not influence personalization behavior on the front end.
This issue affects Sitecore Headless Rendering 14.0.0 version.
To resolve the issue, download and install the hotfix found on this page:
For Sitecore 10.0.0 and Sitecore Headless Rendering 14.0.0: SC Hotfix-439844-1 Layout Service 6.0.0.zip
Be aware that the hotfix was built for a specific Sitecore XP version, 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.