Property 'tab' not valid in version 42.0

Question

When trying to push an existing application to a new Spring '18 org, I get the following error: Property 'tab' not valid in version 42.0.

The application XML is as follows:

<?xml version="1.0" encoding="UTF-8"?>
<CustomApplication xmlns="http://soap.sforce.com/2006/04/metadata">
    <defaultLandingTab>Getting_started</defaultLandingTab>
    <formFactors>Large</formFactors>
    <label>MyApp</label>
    <tab>Getting_started</tab>
    <tab>Audit_log__c</tab>
</CustomApplication>

What's changed?

Answer 1

Noting this here for reference in case others run into the issue - the "tab" XML attribute has been renamed to "tabs" in Spring '18.

So just change the tag name and you're good to go:

<?xml version="1.0" encoding="UTF-8"?>
<CustomApplication xmlns="http://soap.sforce.com/2006/04/metadata">
    <defaultLandingTab>Getting_started</defaultLandingTab>
    <formFactors>Large</formFactors>
    <label>MyApp</label>
    <tabs>Getting_started</tabs>
    <tabs>Audit_log__c</tabs>
</CustomApplication>