Bad state: cannot get a field on a DocumentSnapshotPlatform which does not exist, Firebase Flutter

i am getting data by document id but i get this error:

Bad state: cannot get a field on a DocumentSnapshotPlatform which does not exist

and it's working, i can get the data from firebase by document id but it's giving the error in debug console.

I'm getting data with StreamBuilder:

 StreamBuilder(
          stream: _databaseService.productCollection.doc(docID).snapshots(),
          builder: (context, snapshot) {
            if (!snapshot.hasData) {
              return Center(
                child: CircularProgressIndicator(
                  valueColor:
                      new AlwaysStoppedAnimation<Color>(Colorsx.mainColor),
                ),
              );
            }
            var document1 = snapshot.data;

            return Container(
              decoration: BoxDecoration(
                color: Colorsx.mainColor,
                borderRadius: radius,
              ),
              // color: Colorsx.mainColor,
              child: Column(
                children: [
                  Expanded(
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                      children: [
                        Chip(
                          label: LabelText1("Ürün Adı:  "),
                          backgroundColor: Colorsx.mainColor,
                        ),
                        Chip(
                          shadowColor: Colorsx.mainColor2,
                          elevation: 24,
                          label: LabelText1(document1["productName"] ?? ""),
                          backgroundColor: Colorsx.mainColor2,
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            );
          },
        ),

i couldn't find what is the problem in here but according to my researches, it' related with the map . is there any idea?