'No background points with data in all layers' error

[Arne Loth]

I am just running my first ever MaxEnt model so please bear with me while I ask some pretty basic questions. 

I struggled to get the model running in the first place as I kept getting error messages about covariates not having the same environmental extent. I finally fixed this by re-exporting all files using the same extent and snap raster in ArcGIS, and the files now have the same number of rows, columns, cells, and X/Y coordinates in the ASCII header (I have also double checked this in Word).

Now that I got it running, I'm having the next issue. After suppressing a message that said 'Sample at 320000.0, 267.000.0 in dormouse_samples.csv is missing some environmental data (e.g. hedgerows), I ended up with this error message:

Could this be caused by covariates that contain cells with NoData? Some of my covariates are rasterised shapefiles for environmental features that only cover some parts of my study area (i.e. a particular soil type or landscape feature such as hedgerows). Inevitably, these files have cells with NoData in them - see screenshot below. Does MaxEnt not tolerate NoData? If so, what would be the best way of fixing these files - should I simply run the 'Reclassify' tool and assign a new value to NoData cells? Any suggestions welcome!