I know that prior issues mentioned saveLevel but this is a different method throwing an error. Some key things:

We were running Paper 1.15.2 build #77 and it was fine. We moved the server onto a new host (previously was on a VPS, it's now on a dedicated Minecraft host), Paper was updated to 1.15.2 Build #103 and now backuping the world throws the error above - not saving.

So somewhere between #77 and #103, something's broke OR AutoSaveWorld didn't like us moving the server. To clarify, I've updated the config to reflect the changes in the file system so ASW knows what directory backups are stored in. No luck.

This error is repeated 6x. Always.

[15:04:14 ERROR]: [AutoSaveWorld] Could not dump RegionFileCache java.lang.RuntimeException: Can't find method r with params length 0 at autosaveworld.utils.ReflectionUtils.getMethod(ReflectionUtils.java:49) ~[?:?] at autosaveworld.features.save.AutoSaveThread.dumpRegionCache(AutoSaveThread.java:139) ~[?:?] at autosaveworld.features.save.AutoSaveThread.performSave(AutoSaveThread.java:122) ~[?:?] at autosaveworld.features.backup.AutoBackupThread.performBackup(AutoBackupThread.java:70) ~[?:?] at autosaveworld.features.backup.AutoBackupThread.doTask(AutoBackupThread.java:60) ~[?:?] at autosaveworld.utils.Threads$IntervalTaskThread.run(Threads.java:103) ~[?:?]

EDIT: The world does actually end up backuping it seems. Even though it said "backup complete", it continued to backup the world files and did eventually make one.