Paul M.

Thanks for the fast reply, Mykola.
Actually I got some similar advice when I ran the issue through Perplexity (AI), which suggested a kind of ‘graceful fallback’ code and even trying to make the call through “getAdminNotifier” as well.
Note that I haven’t fully tested this option yet (see below).

My concern is that during a bulk import of WooCommerce products, maybe there is something triggering a warning, or some other kind of notification, that I might be missing (eg., a resource issue?) so certainly I want any errors or notifications to be captured. It seems the crash does not happen if the import batch is only small; it takes several hundred product lines in the import before it happens.
The workaround I have tested so far (successfully), is to deactivate the T.P.T. plugin, run the bulk product import, then re-activate the plugin after that. It looks like this solution works: no fatal errors, and all imported products display their tiered pricing table successfully.

Anyway, I look forward to installing the update release when you have it ready.

Thanks again,
Paul M.

Perplexity AI Code for “Seen notifications”:
…

			<tr>
				<td data-export-label="Tiered Pricing: Seen notifications">
					<?php esc_html_e( 'Seen notifications', 'tier-pricing-table' ); ?>:
				</td>

				<td>
					<?php
/*						$seenNotifications = $this->getContainer()->getNotificationManager()->getSeenNotifications();
 *						
 *						echo esc_html( implode( ', ', array_keys( $seenNotifications ) ) );
 */
                        $seenNotifications = [];
                        $container = $this->getContainer();
                        $notificationManager = null;


                        // 1. Try NotificationManager if the container exposes it.
                        if ( method_exists( $container, 'getNotificationManager' ) ) {
                            $notificationManager = $container->getNotificationManager();
                        }    
                            
                        // 2. If that didn't work, fall back to AdminNotifier if available.
                        if ( ! $notificationManager && method_exists( $container, 'getAdminNotifier' ) ) {
                            $notificationManager = $container->getAdminNotifier();
                        }
                        
                        // 3. Only call getSeenNotifications() if the object actually has that method.
                        if ( $notificationManager && method_exists( $notificationManager, 'getSeenNotifications' ) ) {
                            $seenNotifications = $notificationManager->getSeenNotifications();
                        }
                        
                       echo esc_html( implode( ', ', array_keys( (array) $seenNotifications ) ) ); 
 					?>
				</td>
			</tr>
			<tr>

Thanks for the reply, Moses.
The link and explanation you’ve provided appears to apply to the optional CSV Import Suite plugin.
My issue is with the default, in-built CSV product import feature.
There is no documentation I can find that indicates manual field mapping will only work with certain combinations of column heading names.