QB Issue Resolution:
If you’re in a multi user access, the assistants you added should be on the same shared network so they can access the company files.
To set up and use QuickBooks Desktop multi user please check out this article: Set up a multi-user network. Follow steps 2-7.
Resolution for Issue 'New QB User on a Different Computer log in using QB Desktop' available: Yes (Solved).
Source: Intuit Community forum.
New QB User on a Different Computer log in using QB Desktop: this 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 issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.Support for company files
Quickbooks Repair Pro will resolve it efficiently and affordably. Guaranteed resolution of your issue, or you pay nothing!
Error Recovery for company files [Canada]
E-Tech is the #1 Quickbooks data migration and Conversion service provider.
Additional Support Options: