Cannot migrate old site with Polylang to new site with WPML

This thread is resolved. Here is a description of the problem and solution.

Problem:
The client is attempting to migrate a website from Polylang to WPML using the migration plugin, but the process is stalling and never completes, even after leaving it running for an extended period and restarting several times.
Solution:
If you're experiencing a stalled migration process when moving from Polylang to WPML, we recommend trying the solution outlined in our forum post. Follow the steps provided in the WPML forum topic to resolve the issue.

If this solution doesn't seem relevant or if you continue to face issues, please open a new support ticket with us, and we'll be happy to assist you further.

This is the technical support forum for WPML - the multilingual WordPress plugin.

Everyone can read, but only WPML clients can post here. WPML team is replying on the forum 6 days per week, 22 hours per day.

Tagged: Bug, Exception

This topic contains 5 replies, has 2 voices.

Last updated by Laura 1 year, 6 months ago.

Assisted by: Laura.

Author	Posts
November 16, 2023 at 4:01 pm #14828653
asenV	I am trying to build a new website for a client with old site with 815 posts and Polylang. So on the new installation I have installed Polylang, imported all posts and then saved Polylang languages and enabled WPML and the migration plugin. I have basically followed the instructions from this article: https://wpml.org/documentation/related-projects/migrate-polylang-wpml/ But the process never finishes. Left it for a full day, then restarted it several times for another day and still no results. This is a fresh WP install, only important content are the posts, I can provide admin access. Please help! Link to a page where the issue can be seen: hidden link
November 20, 2023 at 12:03 pm #14876435
Laura WPML Supporter since 05/2018 Languages: English (English ) Italian (Italiano ) Timezone: Europe/Rome (GMT+02:00)	Hi, thanks for contacting us. Please enable the WordPress debug.log and see if there are any errors there https://wpml.org/documentation/support/debugging-wpml/
November 20, 2023 at 12:57 pm #14876917
asenV	Hi! I have enabled debug.log and started the migration process, here's what I got: [20-Nov-2023 12:56:41 UTC] PHP Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/classes/class-mpw_migrate_posts.php:89 Stack trace: #0 /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/classes/class-mpw_migrate_posts.php(24): mpw_migrate_posts->set_original_post_language_details('', Array) #1 /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/migrate-polylang-to-wpml.php(295): mpw_migrate_posts->migrate_posts() #2 /var/web/site/public_html/wp-includes/class-wp-hook.php(324): Migrate_Polylang_To_WPML->ajax_migrate_posts('') #3 /var/web/site/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array) #4 /var/web/site/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #5 /var/web/site/public_html/wp-admin/admin-ajax.php(188): do_action('wp_ajax_mpw_mig...') #6 {main} thrown in /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/classes/class-mpw_migrate_posts.php on line 89
November 20, 2023 at 4:03 pm #14879317
Laura WPML Supporter since 05/2018 Languages: English (English ) Italian (Italiano ) Timezone: Europe/Rome (GMT+02:00)	It's possible one (or more) posts do not have a language assigned? Maybe some kind of draft or some leftover... You can see in the error set_original_language with " " so that's possibly something missing here. You can try this - do a full backup - do a database cleanup with a plugin (I don't have one to recommend specifically) - deactivate all plugins except WPML - start the migration again
November 21, 2023 at 9:51 am #14884845
asenV	Hi! I did what you suggested - database cleanup and deactivating plugins, restarting migration. Here's the error list now: [21-Nov-2023 09:42:54 UTC] PHP Deprecated: ltrim(): Passing null to parameter #1 ($string) of type string is deprecated in /var/web/site/public_html/wp-includes/formatting.php on line 4494 [21-Nov-2023 09:44:54 UTC] PHP Notice: Only variables should be passed by reference in /var/web/site/public_html/wp-content/object-cache.php on line 315 [21-Nov-2023 09:44:54 UTC] PHP Notice: wp_cache_flush() used, this is broadly not recommended. Called in /var/web/site/public_html/wp-content/plugins/wp-hummingbird/core/modules/class-advanced.php line 429 in /var/web/site/public_html/wp-content/object-cache.php on line 320 [21-Nov-2023 09:44:55 UTC] PHP Notice: Only variables should be passed by reference in /var/web/site/public_html/wp-content/object-cache.php on line 315 [21-Nov-2023 09:44:55 UTC] PHP Notice: wp_cache_flush() used, this is broadly not recommended. Called in /var/web/site/public_html/wp-content/plugins/wp-hummingbird/core/modules/class-advanced.php line 429 in /var/web/site/public_html/wp-content/object-cache.php on line 320 [21-Nov-2023 09:44:55 UTC] PHP Notice: Only variables should be passed by reference in /var/web/site/public_html/wp-content/object-cache.php on line 315 [21-Nov-2023 09:44:55 UTC] PHP Notice: wp_cache_flush() used, this is broadly not recommended. Called in /var/web/site/public_html/wp-content/plugins/wp-hummingbird/core/modules/class-advanced.php line 429 in /var/web/site/public_html/wp-content/object-cache.php on line 320 [21-Nov-2023 09:44:55 UTC] PHP Notice: Only variables should be passed by reference in /var/web/site/public_html/wp-content/object-cache.php on line 315 [21-Nov-2023 09:44:55 UTC] PHP Notice: wp_cache_flush() used, this is broadly not recommended. Called in /var/web/site/public_html/wp-content/plugins/wp-hummingbird/core/modules/class-advanced.php line 429 in /var/web/site/public_html/wp-content/object-cache.php on line 320 [21-Nov-2023 09:44:55 UTC] PHP Notice: Only variables should be passed by reference in /var/web/site/public_html/wp-content/object-cache.php on line 315 [21-Nov-2023 09:44:55 UTC] PHP Notice: wp_cache_flush() used, this is broadly not recommended. Called in /var/web/site/public_html/wp-content/plugins/wp-hummingbird/core/modules/class-advanced.php line 429 in /var/web/site/public_html/wp-content/object-cache.php on line 320 [21-Nov-2023 09:44:55 UTC] PHP Notice: Only variables should be passed by reference in /var/web/site/public_html/wp-content/object-cache.php on line 315 [21-Nov-2023 09:44:55 UTC] PHP Notice: wp_cache_flush() used, this is broadly not recommended. Called in /var/web/site/public_html/wp-content/plugins/wp-hummingbird/core/modules/class-advanced.php line 429 in /var/web/site/public_html/wp-content/object-cache.php on line 320 [21-Nov-2023 09:44:55 UTC] PHP Notice: Only variables should be passed by reference in /var/web/site/public_html/wp-content/object-cache.php on line 315 [21-Nov-2023 09:44:55 UTC] PHP Notice: wp_cache_flush() used, this is broadly not recommended. Called in /var/web/site/public_html/wp-content/plugins/wp-hummingbird/core/modules/class-advanced.php line 429 in /var/web/site/public_html/wp-content/object-cache.php on line 320 [21-Nov-2023 09:45:51 UTC] PHP Warning: exif_imagetype(): Stream does not support seeking in /var/web/site/public_html/wp-includes/functions.php on line 3310 [21-Nov-2023 09:45:57 UTC] PHP Warning: exif_imagetype(): Stream does not support seeking in /var/web/site/public_html/wp-includes/functions.php on line 3310 [21-Nov-2023 09:46:11 UTC] PHP Warning: exif_imagetype(): Stream does not support seeking in /var/web/site/public_html/wp-includes/functions.php on line 3310 [21-Nov-2023 09:46:44 UTC] PHP Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/classes/class-mpw_migrate_posts.php:89 Stack trace: #0 /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/classes/class-mpw_migrate_posts.php(24): mpw_migrate_posts->set_original_post_language_details('', Array) #1 /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/migrate-polylang-to-wpml.php(295): mpw_migrate_posts->migrate_posts() #2 /var/web/site/public_html/wp-includes/class-wp-hook.php(324): Migrate_Polylang_To_WPML->ajax_migrate_posts('') #3 /var/web/site/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array) #4 /var/web/site/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #5 /var/web/site/public_html/wp-admin/admin-ajax.php(188): do_action('wp_ajax_mpw_mig...') #6 {main} thrown in /var/web/site/public_html/wp-content/plugins/migrate-polylang-to-wpml-0.4/classes/class-mpw_migrate_posts.php on line 89 [21-Nov-2023 09:47:44 UTC] Cron error for planned event hook: action_scheduler_run_queue, Error code: invalid_schedule, Error message: No planned events., Data: {"schedule":"every_minute","args":["WP Cron"],"interval":60} I also checked the old export site and there are indeed many non translated posts. Could this be the reason? Is there a way to solve it without translating them, since they are like 200+? Thanks!
November 21, 2023 at 10:08 am #14885307
Laura WPML Supporter since 05/2018 Languages: English (English ) Italian (Italiano ) Timezone: Europe/Rome (GMT+02:00)	Can you try the solution proposed here? https://wpml.org/forums/topic/migration-from-polylang-over-to-wpml-is-stalling/
November 21, 2023 at 10:56 am #14885657
asenV	Hey, this solved the issue! Huge thanks! Just a note, that I couldn't find it myself in the forum search for some reason, I tried that first before opening a ticket. Thank you!