Are you wanting to add a new line for an account?  You would first need to create the account on the chart of accounts, then when you go to the budget screen you’ll be able to see the new account and enter in a budget amount for it.

Resolution for 'adding lines issue: 'adding lines to a budget' available: Yes.

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

For more information about resolving issues related to adding lines in Quickbooks/QBO or to get support for the issue 'adding lines to a budget', click the link below: