Gutenberg Editor – Template Doesn’t Match Error

This is a known issue.

A hack would be to disable to the validation completely for the block.
Chris Van Patten provided the following code example:

/**
 * WordPress dependencies
 */
import { compose } from '@wordpress/compose';
import { withDispatch } from '@wordpress/data';
import { InnerBlocks } from '@wordpress/editor';

/**
 * Container block
 *
 * @return {Object}
 */
const Editor = () => (
    <InnerBlocks templateLock={ false } />
);

// This is a hack which forces the template to appear valid.
// See https://github.com/WordPress/gutenberg/issues/11681
const enforceTemplateValidity = withDispatch( ( dispatch, props ) => {
    dispatch( 'core/block-editor' ).setTemplateValidity( true );
} );

export default compose(
    enforceTemplateValidity,
)( Editor );