Create a liability account on your books for the money receive for the event.
Use the make a deposit screen to post the receipts. In the from account use the liability account you just created.
When you pay, use the write checks screen & for the account use the liability account created […]

Resolution for 'Collecting money issue: 'Collecting money on behalf of others?' available: Yes.

The Collecting money 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 Collecting money issue yourself by looking for a resolution described in the article. If it is a complex Collecting money issue or you are unable to solve the issue, you may contact us by clicking here or by using other Collecting money support options.

For more information about resolving issues related to Collecting money in Quickbooks/QBO or to get support for the issue 'Collecting money on behalf of others?', click the link below: