Syncthing failes to start with: WARNING: Database schema: folder db index missing

[nokarukuta]

The log says:

15:45:03 INFO: Migrating database to schema version 9...
15:45:03 WARNING: Database schema: folder db index missing

Seems to be similar to this issue, but using an older binary like 1.3.4 doesn't work because the config files are different:
WARNING: Failed to initialize config: config file version (30) is newer than supported version (29). If this is expected, use -allow-newer-config to override.

[canton7]

I think this looks like a Syncthing question?

[nokarukuta]

The only similar problem I found was here that's why I posted. Any ideas how to fix it?

[hwdsl2]

syncthing/syncthing#6415