UE5.1 can't package : startIndex cannot be larger than length of string

@AumieJaE Hey, my friend.
I just accidentally fix this problem this morning.
What it has to do is “dotnet things” which has a bug when run from a machine with use non-standard region DateTime.

I changed Windows Regional Format to [English United States] and restarted the computer. Then I packaged the project successfully at least 2 times. I will try with my working project today too.

Maybe this can solve your issue too.

This is the link they’re talking about “dotnet things”
https://github.com/dotnet/sdk/issues/23148