Old laptop, 32bit 1 GB RAM, W10, MP 188.8.131.52:
GeoTiff 5.32 GB doesn't work, everywhere 'Invalid 0.00m' in target area and outside, NO SRTM.
Console shows OutOfMemoryException as in post #1.
GeoTiff 2.66 GB same as above
GeoTiff 1.68 GB o.k., so 2 GB limit for 32 bit System seems to be active.
Tried three sub 2 GB files (1.18, 1.57, 1.68 GB):
they work as expected on the 64 bit system (seems to load faster than 1 big file of same area).
On the 32 bit 1 GB system the 1.68 GB works correct, the other two files not. When the mouse crosses the border to the 1.18 GB or 1.57 GB file, the last value in height and GeoTiff or SRTM is displayed and doesn't change until the mouse exits the area.
Should the files overlap ? Any problems expected if the areas overlap ?
The 1.68 GB file works as single GeoTiff, the two smaller ones do not work (OutOfMemoryException). As you mentioned a possible width problem (the two smaller ones are a North and a South part), I tried a vertical cut to get an East and West slice. Unfortunately same result. The mystery for me is, that the 1.68 GB is the biggest one and has almost same width as the North section and it is wider than the South section.
While I have your attention, can I motivate you to improve the Survey Grid tool ? It is really lacking for flying in the mountains and I could tell you my ideas for necessary extensions - wouldn't be too much work I hope.