UnsuccessfulResponseException: 500 when syncing with wallabag.it

[pssandhu]

Description: Cannot sync android app with wallabag.it. Results in UnsuccessfulResponseException: HTTP response: 500

Steps to reproduce:

1. Open android app
2. Manually refresh

Alternative steps:

1. Share a link from another app to the wallabag app
2. The popup with the Star, Mark as Read, Tag and Open buttons appears
3. Pressing the Open button leads to the error and it never loads

App details:

• Android app version: 2.5.3 (f-droid)
• Android 16, stock
• Google Pixel 6a

Server:

• I'm using the wallabag.it instance (in other words, i am not self-hosting so have no control over the configuration)

Additional details:

• I have no errors when using the same sever with the same account from the website or the browser extension
• This looks like a repeat of 500 error from wallabag.it while syncing #1247 which didn't lead to an answer
• I have not yet tried deleting the app's data or reinstalling it

Stack trace

Server error
wallabag.apiwrapper.exceptions.UnsuccessfulResponseException: HTTP response: 500 
Stacktrace:
wallabag.apiwrapper.exceptions.UnsuccessfulResponseException: HTTP response: 500 
	at wallabag.apiwrapper.WallabagService.checkResponse(WallabagService.java:1525)
	at wallabag.apiwrapper.WallabagService.checkResponseBody(WallabagService.java:1503)
	at wallabag.apiwrapper.WallabagService.execAndCheckBody(WallabagService.java:1499)
	at wallabag.apiwrapper.WallabagService.lambda$modifyArticle$7$wallabag-apiwrapper-WallabagService(WallabagService.java:868)
	at wallabag.apiwrapper.WallabagService$$ExternalSyntheticLambda4.run(D8$$SyntheticClass:0)
	at wallabag.apiwrapper.NotFoundPolicy.call(NotFoundPolicy.java:140)
	at wallabag.apiwrapper.NotFoundPolicy.call(NotFoundPolicy.java:133)
	at wallabag.apiwrapper.NotFoundPolicy.call(NotFoundPolicy.java:128)
	at wallabag.apiwrapper.WallabagService.modifyArticle(WallabagService.java:868)
	at wallabag.apiwrapper.ModifyArticleBuilder.execute(ModifyArticleBuilder.java:103)
	at wallabag.apiwrapper.ModifyArticleBuilder.execute(ModifyArticleBuilder.java:86)
	at fr.gaulupeau.apps.Poche.service.workers.OfflineChangesSynchronizer.syncArticleChange(OfflineChangesSynchronizer.java:368)
	at fr.gaulupeau.apps.Poche.service.workers.OfflineChangesSynchronizer.syncOfflineQueue(OfflineChangesSynchronizer.java:118)
	at fr.gaulupeau.apps.Poche.service.workers.OfflineChangesSynchronizer.synchronize(OfflineChangesSynchronizer.java:68)
	at fr.gaulupeau.apps.Poche.service.tasks.SyncOfflineChangesTask.run(SyncOfflineChangesTask.java:17)
	at fr.gaulupeau.apps.Poche.service.tasks.ActionRequestTask.run(ActionRequestTask.java:25)
	at fr.gaulupeau.apps.Poche.service.TaskService$$ExternalSyntheticLambda2.run(D8$$SyntheticClass:0)
	at fr.gaulupeau.apps.Poche.service.TaskService.run(TaskService.java:162)
	at fr.gaulupeau.apps.Poche.service.TaskService.$r8$lambda$7B6NdHPPL8YMNadJyfVPhGC-s2M(Unknown Source:0)
	at fr.gaulupeau.apps.Poche.service.TaskService$$ExternalSyntheticLambda1.run(D8$$SyntheticClass:0)
	at java.lang.Thread.run(Thread.java:1119)

[di72nn]

I have not yet tried deleting the app's data or reinstalling it

No need for such measures.

If it's an option, do this: #990 (comment).
I haven't looked into it yet, but on modern Android versions you may no longer have access to the directory where the app saves the local changes to, so that may be a problem. But you can still do the "remove first local queue item" to stop having that issue.

It would be useful to find out why server can't handle that change, so if you manage to access that local changes file, please share the first item from the list.

(And it's not a URL in your case - it's some article change (which is unusual), so even in the worst case you shouldn't lose any articles)

[pssandhu]

Thank you for the very helpful reply. I didn't know about these debugging features in the app.

I have managed to access the local changes text file. The first item is:

id; action; articleId; localArticleId; extra; extra2
1; ARTICLE_CHANGE; 26332298; null; TAGS; null

Using the website, I can confirm that an article with id 26332298 exists in my account's data.

Removing the first item in the local queue has worked and it now syncs again. Thank you!

[janxkoci]

I never really get an error message, the app just stopped syncing local changes at the end of August (right after I paid for hosted instance, incidentally).

The alternative steps to reproduce were useful, except my app just loads indefinitely, without showing any error. The fix of removing first item in the queue worked and it is now syncing again! Thanks for that.

How do I check if the ID of the last item is present in the web app? Oh, I just entered the ID into the URL, like this: https://app.wallabag.it/view/<offending-id>. This page shows fine in both android and web apps, including tags. No idea why it was blocking the sync.

[janxkoci]

It just happened again today. Here are the steps:

• I've saved a new link to wallabag from my phone's browser, and I've added two tags.
• The article got synced and showed in the web app.
• I've opened the app, opened the article, and added one more tag. This change also synced. Correction: the new tag didn't sync to web app.
• Sync is broken now, no new items are synced (e.g. new item added on my laptop is not pulled to my phone).
• Deleting last queue item, as suggested above, fixed the issue and new item was pulled.

I believe that editing the item (by adding a new tag) is what broke the sync.