Hi! Normally if you enter the bbox and the green "Custom selection confirmed!" text appears, that custom bbox was accepted. Then you only need to select a world and start the generation. As of now the bbox won't be displayed in the map, I still have to implement that. So your input should normally work. Or is there any other error you encountered?
Thanks for the report! :)

The world takes a very long time to build. a lot of time is stuck on Fetching data 1%, Processing data 35-40%. If you select the same area through GUI and not settings, everything is fine.

@louis-e

Maybe there are some CLI flags-arguments to start? To specify directly without GUI.
i tested arnis.exe --path="C:/YOUR_PATH/.minecraft/saves/worldname" --bbox="min_lng,min_lat,max_lng,max_lat" but its doesnt working

Thanks for letting me know, I'll look into this!
Can you confirm that this bbox input is affected?: 36.118816,-115.180104,36.114801,-115.172899

Thanks for letting me know, I'll look into this! Can you confirm that this bbox input is affected?: 36.118816,-115.180104,36.114801,-115.172899

yes,

I've tested this on other PCs as well, a more powerful one

I still cannot replicate this problem on my machine, but I improved the error handling a bit which will be included in the next release. I hope this will help us to figure out the problem! :)

I check this on latest release. Same.

I still cannot replicate this problem on my machine, but I improved the error handling a bit which will be included in the next release. I hope this will help us to figure out the problem! :)

Are you using Windows?

Weird, could you provide the log file (C:\Users\USERNAME\AppData\Local\com.louisdev.arnis\logs)?