Do you have one device where all your notes are available (or all you need ?) ?
Have notes been changed since the last backup or is the backup up-to-date ?
Have you edited notes on other devices ?
If the answers to these questions are YES / NO (or don't care) / NO
then goto -> options -> sync -> advanced ->
and just upload your local profile from "that" first device.
I tried several times your suggestion but the message remains.
I tried on a laptop the previous version of Joplin with the same profile and the message does not appear. I updated to the latest version, without changing anything, and the message appears again.
Evidently it is something in the latest version of Joplin. The message also appears on my Android phone.
Thank you. The same happened to me. After clicking "Retry all," I thought the error persisted. Exit the application completely by right-clicking on the application icon and selecting "exit," then restart the application. The error should be resolved.
I not only closed Joplin completely but also shut down the pc. The message reappears. I had already tried this method two days ago and every day I shut down the pc.
Thank you very much for your suggestions, but it seems to me that my problem is different from yours.
I'm sorry to hear that the solution didn't work for you. You can click on the "Export debug report" button and share the relevant report here for developers to review.
Additionally, you may try completely uninstalling Joplin from both your computer and mobile device, then reinstalling it. This didn't work for me, but I think it's worth a try.