I have a QGIS project linked to an ESRI file geodatabase. It was first built a few months ago and hasn't been opened since. I just re-opened it and noticed that the layers looked odd. Upon further investigation I noticed that there was a layer mismatch with the file GDB, so what I thought were points for animal habitat locations look more like polygons for geotech reports, and all the layers seem to not be what the layer says it should be, confirmed by looking at the attribute tables.
I suspect this is due to the QGIS layer source making reference to a layerID in the file GDB, and suspecting that ESRI does some cleanup/shuffling in the background ordering of the gdb layers, similar to when it reassigns OID's to records to clean up deleted record numbering holes. So when QGIS thinks layer 23 = bird habitat, it actually accesses layer 23 = geotech reports, instead of accessing it through a FeatureClass name.
Has anyone else noticed this? Does anyone know a robust way of linking a QGIS project file to a FileGDB and not have it do this 3 months later? I am going to try the ESRI driver for accessing the file GDB instead of the OpenFile GDB and see if that fixes it, but will need to wait a while to see if the GDB reshuffles its layers.