If you use X-Plane through Steam you must only ever use Steam to update. Using the Laminar Research installer will break the DRM. To fix this you will need to delete the DRM files. They are located in:
The user’s local app data folder, e.g. C:\Users\nnnn\AppData\Local\.
You will want to delete any & all of these possible files (they will probably have an 11 in the name):