When I try export map in Preset Style "AT5 Map with color gradient shaded relief" this error appears (see bellow).
If i decrease Map definition Area from 12km:6km to 3:6 km RM work correctly.

The SynchronizationContext can not be used as TaskScheduler.


   In System.Threading.Tasks.SynchronizationContextTaskScheduler..ctor ()
   In ReefMaster.ViewModels.ProjectLayers.ShadedReliefMapLayerViewModel. # = QxC45XwICy8p0d8M1SLr20BF4VF68ij_5gLoYyaTPHlY = (gridded_depth_data # = qdcy_ $ b0AII33d2Y86QOc9Q ==)
   in ReefMaster.ViewModels.ProjectLayers.ShadedReliefMapLayerViewModel..ctor (# = qJtaEnietV28CpF2VHQxrOnYJcVTgjMSlH6yK2t50T_oVZfTzkFBEMQKAl6br1R4Yvw $ fLChHTWdWCqBxilcDTA == mapLayer, # = q2q__hgnq9_qsNwVKcnWEdaJDbvy $ vK_XAPj0NYx5rvaVdbmLdAnp1Ov9oppaNfNZolEWHS5l7Y6Wz9KWcLmpvg == viewModelManager, # = qmSu0AykwwC6wE7pvWycVBNcRAK7FtvstaSPxXsXEpV32S6wsZYyAU2AFsTKJ96MenfxiyufPWqVoaW5qsAEoKFwkxKbgdfGPU9_KtCIOA34 = mapLayerViewModelDisplayManager)
   in -.dje_qEZSA68QF4HY4RUQKE6D2FPUKGXSWBW8H2M5SND9VA8WQ4R5SDFJWLGRP56B54HVZPHE2XXD4EM768V8LTS6W8KGXTNTDEYKRDQPS6E2_ejd. # = qPhHjRGnJxb50rAIl5SJbBSKHqz2sXYmmQPnSOjUHBzA = (MapLayer # = qaPrqzIzIuyXG17UOj15ckg ==)
   in -.dje_qEZSA68QF4HY4RUQKE6D2FPUKGXSWBW8H2M5SND9VA8WQ4R5SDFJWLGRP56B54HVZPHE2XXD4EM768V8LTS6W8KGXTNTDEYKRDQPS6E2_ejd. # = qm1qTOLY13qrDE2c6mfZxNpZYAkhrvyVFguI2o0eFU0E = (IEnumerable`1 # = q47h_X3wFVFW6qvurj3pJUw ==)
   in -.dje_qZRK9ZJP4PLRTHF3GH9NZBL23EDHCEWX3YWHJ386C28B2DSZMHEWM2V5Z7UADZ8K84K9YDQZ9AJJY8QW2HSB75TEBRSWZGZQU5VGTC82_ejd. # = q $ cWfU8uPY68clExVCeTIXjeGe9miRuTkoSHVe9DHG2Q =. # = qQ6IgdvBWHaZM2uAnRcNb0msT5G8itDfCl $ 4mL $ DmFCY = ()
   in # = qPTOTHk4CrQgT9uOg7snUwz $ MIx7yNuh7b7x_HBYkcU8 =. # = qsPkUaL8N1ZKZh1eBRC8gNhZ $ 4DKkxW2ficCv5_D2pvw =. # = qj7yZ7XXYgu5YKUDfEb5OV2tTQm83I83n1Z_QN7DFLck = ()
--- End tracing the stack from the previous location where the exception occurred ---
   In System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (Task task)
   In System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (Task task)
   in -.dje_qZRK9ZJP4PLRTHF3GH9NZBL23EDHCEWX3YWHJ386C28B2DSZMHEWM2V5Z7UADZ8K84K9YDQZ9AJJY8QW2HSB75TEBRSWZGZQU5VGTC82_ejd. # = qFedT $ C4u37gvut48C3mSbUyGmpfTUsvQwtD76KEjYM8 = .MoveNext ()

Thanks - will look into it.

Not sure if will help, but Instead of using the "preset" style export, I export generically and then designate it as an AT5 shaded relief in the box that pops up. I think I get the same thing. Its a perfect AT5 with shaded relief, contour lines, and the palette I chose. I'm doing some huge map today with success. (40 miles X6 miles)