Updated my own Sage 100 from 2019.1 to 2019.2 and could not finish the conversion process.  Failed on AR_CashReceiptsHistory file, first pointing to an IPBAB folder (instead of ARBAB), then refusing to even let me delete and recreate.  Found the issue is a new key involving EinvoiceTransactionID (or close to this).  Had to delete they key in order to let the conversion continue.

Had a client where I updated them last night between the same 2 versions and did NOT have this issue.  Not sure what the diff is...