Two of my bot tasks, [[https://github.com/AntiCompositeNumber/AntiCompositeBot/blob/master/src/nolicense.py|NoLicense]] and [[https://github.com/AntiCompositeNumber/iNaturalistReviewer|inrbot]] started generating frequent authentication errors like the following:
```
2021-01-18 12:36:40 pywiki ERROR: Retrying failed OAuth authentication for commons:commons: The authorization headers in your request are not valid: Nonce already used:
```
The first was recorded at 2020-12-10 17:42:12 UTC. The problem went away between Dec. 16 and Jan 15, except for one occurrence on Jan 6. Since then, I have been getting errors every few hours.inrbot runs constantly, while NoLicense is started fresh every hour. The INaturalistReviewBot account is used solely by the inrbot task, while NoLicense runs as AntiCompositeBot with several other tasks. One of the other AntiCompositeBot tasks has had this error once. All errors have been on commons.wikimedia.org, but that is likely just selection bias as my enwiki tasks make significantly fewer edits. Both use OAuth to login using pywikibot.
``` name=Timestamps of errors, lines=5
2020-12-10 17:42:12
2020-12-14 20:18:52
2020-12-16 11:08:20
2021-01-06 17:06:19
2021-01-14 17:20:16
2021-01-14 19:15:29
2021-01-14 21:02:00
2021-01-14 23:45:44
2021-01-15 07:12:43
2021-01-15 07:25:53
2021-01-15 08:05:07
2021-01-15 09:05:16
2021-01-15 18:05:19
2021-01-15 19:05:17
2021-01-15 23:14:11
2021-01-16 01:41:47
2021-01-16 10:11:54
2021-01-16 10:13:46
2021-01-16 15:05:52
2021-01-16 15:06:48
2021-01-16 16:05:32
2021-01-16 17:36:13
2021-01-16 18:21:22
2021-01-16 21:05:53
2021-01-17 07:05:23
2021-01-17 10:11:27
2021-01-17 10:11:34
2021-01-17 11:06:24
2021-01-17 14:05:25
2021-01-17 17:05:16
2021-01-17 20:29:02
2021-01-17 20:55:04
2021-01-17 21:06:07
2021-01-17 21:26:31
2021-01-17 21:26:34
2021-01-17 21:42:30
2021-01-17 21:42:32
2021-01-17 21:52:30
2021-01-18 02:07:41
2021-01-18 02:42:00
2021-01-18 09:51:32
2021-01-18 12:05:20
2021-01-18 12:36:40
2021-01-18 20:05:25
2021-01-18 21:18:48
2021-01-18 22:05:17
```