run a quickreport for one of the items and see if the inventory adjustment appears on the list.  open the inventory adjustment which should show all the items. Ctrl D will delete the entire adjustment.

Resolution for 'adjustment posting issue: 'How can I delete inventory reconciliation adjustment posting?' available: Yes.

The adjustment posting issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the adjustment posting issue yourself by looking for a resolution described in the article. If it is a complex adjustment posting issue or you are unable to solve the issue, you may contact us by clicking here or by using other adjustment posting support options.

For more information about resolving issues related to adjustment posting in Quickbooks/QBO or to get support for the issue 'How can I delete inventory reconciliation adjustment posting?', click the link below: