How to newly add an account to a tree

Summary:

I would like to know how to add an account that has already been added to one tree into another tree.

Content (please ensure you mask any confidential information):

I would like to know how to add an account that has already been added to one tree into another tree.

After using ChartofAccountsSegmentValuesandHierarchiesImportTemplate.xlsm to add accounts to a tree and then executing the flattening process, the following error occurred:
Error details:
ORA-01403: ORA-06512: "FUSION.FND_TREE_UTILS_PVT"

Could you tell me what might be the possible cause of this error?

Also, regarding ChartofAccountsSegmentValuesandHierarchiesImportTemplate.xlsm, since the accounts had already been added, I did not enter anything in the sheet