The bug

Due to the fix of MC-188389, the "datapacks" string is now inconsistent with the "data pack" string in the datapackFailure.title text:

Errors in currently selected datapacks prevented the world from loading.

You can either try to load it with only the vanilla data pack ("safe mode"), or go back to the title screen and fix it manually.

Here is a part of the en_us.json language file that demonstrates the bug:

{
  "datapackFailure.title":  "Errors in currently selected datapacks prevented the world from loading.\nYou can either try to load it with only the vanilla data pack (\"safe mode\"), or go back to the title screen and fix it manually."
}

Fix

The text should be the message shown below to promote consistency:

Errors in currently selected data packs prevented the world from loading.

You can either try to load it with only the vanilla data pack ("safe mode"), or go back to the title screen and fix it manually.