PLEASE let me know how you resolved this.  We had quickbooks do the conversion for us after I made sure the books for 2019 were closed and to the accountant.  The conversion has been an absolute nightmare.  Quickbooks will not help me at all.  Now they have told me to speak with the accountant or a pro advisor to fix the errors.  The checking account reverted back to 2011 and is unreconciled and came over with  a zero beginning balance.  The employees info all had to be put in again.  Today I tried to post the payments made by credit cards and that goes way back.   I have used Quickbooks for 15 years and have always been happy.  This is such a bad experience.  We are still paying for both Enterprise and Online as I do not dare to cancel online yet. I am trying to get some sort of help and/or refund--not getting any response at  this point. HELP!