If you are receiving error code 401, try the following steps to troubleshoot the issue.
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If you have trouble signing in to your Zoom account, we recommend clearing cache and cookies in your device or in your browser. Removing information stored in cache and cookies may help resolve a variety of issues when using other Zoom features.
In addition to clearing your browser's cache and cookies, flushing the computer's DNS cache will help resolve Zoom error code 401.
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
Another reason you may be receiving Zoom error code 401 is that you—the account owner or admin—are trying to create a separate account for the new user. As the account owner and/or admin, you will have all the billing information in one place, rather than in two separate accounts. This way, you can make several users within one billing account.
You must add the new user to your account.
If you are still receiving error code 401, submit a request to Zoom Support for troubleshooting assistance. Please provide the following: