No details for error

[zstadler]

Maputnik version: v2.1.1
Browser: Firefox
OS: Windows

Description of the bug:
If one creates a new layer, and accidentally uses a name of an existing layer, the name of the new layer will be colored in red, but no other explanation of the error is given.

Steps to reproduce the behavior:

1. Open the "Toner" style
2. Add layer name "waterway". For example:
   
3. The name of the new layer is red, and that's it

Screenshots:

[zstadler]

@louwers ,

Thanks for fixing this issue by preventing the creation of a new layer with an existing name.

The same unexplained error can also happen when an existing layer is renamed to a name of another layer.

This can be done by editing the layer's ID field. For example, renaming the "water" layer to "waterway"

or by editing the layer's JSON definition

Is it possible to address these scenarios too?