Apparently some recentchanges rows which we inject into wikibase clients don't have their "id" (referring to `wb_changes.change_id` on the repo) set:
```
wikiadmin@10.64.32.115(enwiki)> SELECT rc_params FROM recentchanges WHERE rc_id = 1245837094 LIMIT 1\G
*************************** 1. row ***************************
rc_params: a:1:{s:20:"wikibase-repo-change";a:14:{s:2:"id";N;s:9:"object_id";s:8:"Q5538841";s:4:"type";s:20:"wikibase-item~update";s:11:"revision_id";s:10:"1147155130";s:7:"user_id";s:5:"95338";s:4:"time";s:14:"20200331142533";s:11:"entity_type";s:4:"item";s:7:"page_id";i:5299020;s:9:"parent_id";i:1034014476;s:7:"comment";s:120:"/* wbsetreference-add:2| */ [[Property:P7859]]: lccn-n87895055, [[:toollabs:quickstatements/#/batch/25615|batch #25615]]";s:6:"rev_id";i:1147155130;s:9:"user_text";s:16:"Vladimir Alexiev";s:15:"central_user_id";i:15868969;s:3:"bot";i:0;}}
1 row in set (0.00 sec)
```
```
php > print_r(unserialize('a:1:{s:20:"wikibase-repo-change";a:14:{s:2:"id";N;s:9:"object_id";s:8:"Q5538841";s:4:"type";s:20:"wikibase-item~update";s:11:"revision_id";s:10:"1147155130";s:7:"user_id";s:5:"95338";s:4:"time";s:14:"20200331142533";s:11:"entity_type";s:4:"item";s:7:"page_id";i:5299020;s:9:"parent_id";i:1034014476;s:7:"comment";s:120:"/* wbsetreference-add:2| */ [[Property:P7859]]: lccn-n87895055, [[:toollabs:quickstatements/#/batch/25615|batch #25615]]";s:6:"rev_id";i:1147155130;s:9:"user_text";s:16:"Vladimir Alexiev";s:15:"central_user_id";i:15868969;s:3:"bot";i:0;}}'));
Array
(
[wikibase-repo-change] => Array
(
[id] =>
[object_id] => Q5538841
[type] => wikibase-item~update
[revision_id] => 1147155130
[user_id] => 95338
[time] => 20200331142533
[entity_type] => item
[page_id] => 5299020
[parent_id] => 1034014476
[comment] => /* wbsetreference-add:2| */ [[Property:P7859]]: lccn-n87895055, [[:toollabs:quickstatements/#/batch/25615|batch #25615]]
[rev_id] => 1147155130
[user_text] => Vladimir Alexiev
[central_user_id] => 15868969
[bot] => 0
)
)
```
AFAICT we don't use this information anywhere, so one course of action //could// be to simply remove the reference.