Yes, with it not built into the map, the map writes fine. I did more testing... if I don't select anyone with the people picker, it submits fine, but as soon as I pick people, if gives that error. Hmmm...I just tried picking only one person, and it submitted fine. So, it's only when I pick more than one person that I get that error. I checked the list field properties and I do have it set to allow multiple selections (people only, no groups).
So, thinking it may be the concatenation... I looked back at your blog and response to the post (the 2 links you sent). In the blog you have a # before the "-1;" for the 2nd person (see screenshot), but it doesn't look like the concat formula does (from your response), which I copied/pasted.
Originally I was using... substring(xdMath:Eval(xdMath:Eval(../my:pp_Draftgroup/pc:Person/pc:AccountId[. != ""], 'concat(";-1;#", .)'), ".."), 2). So I added the other # to get: substring(xdMath:Eval(xdMath:Eval(../my:pp_Draftgroup/pc:Person/pc:AccountId[. != ""], 'concat(";#-1;#", .)'), ".."), 2)
Resulting formula: # -1;#EVERPACK\hastd;#-1;#EVERPACK\wilsog
So, I get the error because of the initial #, but not when I manually remove it from the text box. So manually manipulating it, I can get it to submit multiple people. Now to figure out how to get rid of that first # that the concatenation is adding (but I need it before the 2nd person).
So, I wrapped your formula in a substring-after function... substring-after(substring(xdMath:Eval(xdMath:Eval(../my:pp_Draftgroup/pc:Person/pc:AccountId[. != ""], 'concat(";#-1;#", .)'), ".."), 2), "#") and now it works :)
Thanks for all your help! I never would've gotten it without you!
(the screenshot is from your blog post, and shows what I was missing in my formula)