QB Issue Resolution:

Targets of a QB transaction provides information about the transaction and includes the target accounts, target names, target memos, target amounts, etc. Migrating data to QBO only allows Quickbooks files with less than 350,000 targets to be migrated. If your data file has more than 350,000 targets, you will need to reduce the target count in your Quickbooks data file by running a condense or using a supercondense service prior to uploading it to Quickbooks Online.