Enabling Print Jobs causes error

We are running Essentials 3.8 but this problem also seems to exist in 3.6.

I have a map template that works fine if print jobs is turned off, but if I enable print jobs the job always fails.

 

The tiles seem to be generated okay because I see png files in the Print Jobs\xxxxxxx directory.  The status.dat file doesn't give much detail except for this error:

<Errors>

 

    <string>System.InvalidOperationException: Unable to create one or more tiles.

 

   at Geocortex.Gis.CoreMap.DrawTiles(MapDrawOptions options, PrintJob printJob)

 

   at Geocortex.Essentials.MapBase.DrawTiles(MapDrawOptions options, PrintJob printJob)

 

   at Geocortex.Essentials.Printing.EssentialsPrintJob.DrawTiledMap(MapBase map, MapTemplateReportSettings settings, ImageDescriptor mid)

 

   at Geocortex.Essentials.Printing.EssentialsPrintJob.AcquireMapImages()</string>

 

  </Errors>

There is no indication of what tile couldn't be created or why it couldn't be created.

 

All permissions should be okay - the Essentials and EssentialsAdmin accounts have read and read/write where the documentation says they should.

I have tried using Process Monitor to see if there are any other permission issues (unable to write, etc.) but there don't seem to be any.

Has anyone else encountered this problem?

Peter.