Weird LWC Error on template if:true

Question

<template if:true={isMultiEntry}>TRUE {isMultiEntry} </template>
It displays on the page as: TRUE false  

This is launched from an Aura Wrapper component in a button on a record detail page. There are errors on loading the page itself, but none on launching the component.

There are errors on the page but, but based on the stack traces, none point to my component. Also, all are generated before launching my component (my component does not generate any errors) and there are no LWCs that are present on the page outside of an aura-wrapper button.

Errors on the page load itself are:

• Error: [LWC error]: The insertBefore method is available only on elements that use the lwc:dom="manual" directive.

• Error: [LWC error]: The replaceChild method is available only on elements that use the lwc:dom="manual" directive.

• Error: [LWC error]: The appendChild method is available only on elements that use the lwc:dom="manual" directive.
• Error: [LWC error]: Invalid event type "WireContextEvent" dispatched in element . Event name must 1) Start with a lowercase letter 2) Contain only lowercase letters, numbers, and underscores
• Uncaught (in promise) Error: getAllTabInfo() - Failed to get tabInfo.

Answer 1

Errors in console:

All those errors are because of errors in the way standard LWC components are handled in Aura context or vice versa. These have been there (some added/fixed in major releases) from long time and we see them in debug mode.

Note that errors in console for standard components will not really affect your implementation. These errors are custom errors generated by LWC layer handler and apparently few standard LWC components are not in-line with best practices/way of implementation

Component problem

isMultiEntry is setting to String 'false' and so it is showing up. isMultiEntry should be boolean false.