I have a series of layer files (.lyrx) which have stopped working in ArcGIS Pro 2.8 with the error:
ERROR 000966: The input layer is not valid
Is there any way I can upgrade them without access to the original project I used to create them. I need the thematic setup (standard class breaks, standard colours) and I don't want to spend hours setting them all up again.
a layer package would have been more useful since it packages the data as well.
If you have access to the original data you might be able to recover the references.
Alternately if you need references to the properties of the *.lyrx then you have to use the mapping module