Users have reported the following to us:
If your source and target are both on the API v50 (Winter '21) and
you are deploying a profile that contains this in the source
You will get the validation error:
You can't edit tab settings for DelegatedAccount, as it's not a valid tab.
This is happening because Salesforce API does not support
DelegatedAccount in tabs. Please report this to Salesforce support.
If you are deploying from org to org, you can workaround this error by removing the
DelegatedAccount custom object from your metadata filter. This will prevent the profile from retrieving the tab visibilities for this custom tab, and therefore not deploy this section.
If you are deploying from Git (where all components of a profile are retrieved) you can work around this and still deploy the Profile by:
Downloading the deployment package, from the
Download packagebutton on the deployment summary page before the deployment. (See here for more instructions)
.profilefile (using software that can view the XML such as Notepad, TextEdit or VSC) to delete the four lines that reference
Create a new comparison with
Local filesas the modified
.profilefile (with the valid
package.xml) and deploy.
Hopefully this workaround will help you deploy your profile while this Salesforce metadata API bug is being investigated.