Yeah, Doug is on to something there.
I just got done playing around with mine. I believe the error has to do with the AutoChart program itself, as well as computer speed, memory, and processing data.
I played around with different settings.
Make sure you start new AutoChart session (Go to File --> New). I played around with the internal map size. First, I had the internal map size set at 3000 x 3000 m, and the SI settings of Image resolution [m] set at 0.125 (1/8). When I clicked Load SI Data, it was able to load the whole SI mosaic for my sonar recording.
Then, I tried changing the SI resolution to 1/16. I get a popup with an orange triangle and exclamation point, and I clicked OK. Then I clicked Load SI Data, selected my sonar recording, and it was able to load the whole SI mosaic without error again.
Then, I tried changing the SI resolution to 1/32. I get a popup with an orange triangle and exclamation point, and I clicked OK. Then I clicked Load SI Data, selected my sonar recording, and it was able to load the whole SI mosaic without error again.
Then, I tried changing the internal map size to 5000 x 5000 m under 'General settings'. When you change the internal map size, you have to close AutoChart and reopen it for that change to take effect. So, when I reopened the program, I tried to click 'Load SI Data' again. This time, I got the error message "You do not have enough memory for the current resolution setting. Please reduce the sidescan resolution, or the size of the internal map."
So then I tried reducing the internal map size to 4000 x 4000 m, closed the program, and reopened. SI resolution still set at 1/32, I got the same error message when trying to click 'Load SI data'.
So then I tried reducing the internal map size to 3000 x 3000 m, closed the program, and reopened. SI resolution still set at 1/32, I got the same error message when trying to click 'Load SI data'.
So then I tried reducing the internal map size to 1000 x 1000 m, closed the program, and reopened. SI resolution still set at 1/32, and this time I was able to click 'Load SI data', and did NOT get the error message. I opened the sonar recording file, and it drew the SI mosaic just fine.
So, then I increased the map size to 3000 x 3000 m again, closed the program, and reopened. SI resolution was still set at 1/32, and like I expected, got the error message again when I clicked 'load si data'. This time, instead of adjusting the internal map size, I decreased the SI resolution to 0.125 (1/8) again, back to where we started. I click 'load si data', selected my sonar recording, and it drew the sonar recording again just fine.
So... long story, but here's what I concluded. Just like the error message states. If you have your internal map size too large, and you're trying to have AutoChart draw the SI mosaic at a high resolution like 1/32, the program doesn't have enough memory to perform that task. You need to either reduce the internal map size and reopen AutoChart, or reduce the SI resolution down to 1/8, in order for AutoChart to draw the SI imagery.
I really liked seeing the highest resolution for the SI imagery though, when I had my internal map size smaller and the SI resolution at 1/32. It was really detailed.
So, I guess my point is, if you want to see really high resolution (1/32) in your side imaging, you'll have to use a smaller internal map size setting, and just move your map and refresh your imaging more often.
Hopefully that all makes sense.