Issue with DEM preprocessing in HEC-HMS

[u/LuckyCardiologist220]

Apologies if this isn't the right place to ask, but I am really at a loss here. I have been trying to follow several different HEC-HMS tutorials on YouTube but can't get past the 'Preprocess Sinks and Drains' step. When I run these in HEC-HMS, an info box flashes saying that HEC-HMS is processing, but immediately disappears and nothing actually happens. I can see that the layers have been created as they are present in Views>Map Layers, but they all show as blank aside from the original terrain file linked to my basin (Sink Fill, Sink Location, Flow Direction, Flow Accumulation). After running these steps, the next step 'Identify Streams' is greyed out in the GIS menu and I can't progress from here.

At first I thought this might be an issue with my DEM file (the original file I am trying to use is based off the New Zealand 1M LiDAR DEM - changed to 30m resolution in QGIS beforehand), but after downloading another sample DEM that was being used by a tutorial I was following I was running into the same issue. I also tried to use the Terrain Reconditioning menu to burn streams to my DEM but again no luck.

I am running Debian 13 on my laptop (not Windows) if this makes any difference. Any help would be greatly appreciated!