QuickBooks Error code c=51: This warning message shows that QuickBooks is not able to find the TxList file also this error occurs when you try to remove txList from txLists list, but unable to find it. In this blog, we are going to discuss about QuickBooks Error code c=51 and it's solutions. Link: https://www.proaccountantadvisor.com/fix-quickbooks-error-code-c-51/