Experiencing the same issue, also with older format versions (1.26.10, 1.21.80, 1.21.0).
This happens when loading the SplitBlocks or MultiBlocks Marketplace Addon. Both Addons still work perfectly fine but keep producing these error log messages.Best
Experiencing the same issue, also with older format versions (1.26.10, 1.21.80, 1.21.0).