Unable to apply Style to leaf 'value.isInline || value.isIgnored || value.isEmpty'

[Yusuf-Uluc]

I get this error:

The following assertion was thrown building Builder:
Unable to apply Style to leaf: {Attribute{key: header, scope: AttributeScope.BLOCK, value: 1}}
'package:flutter_quill[/src/models/documents/nodes/leaf.dart]()':
package:flutter_quill/…/nodes/leaf.dart:1
Failed assertion: line 30 pos 12: 'value.isInline || value.isIgnored || value.isEmpty'

when I try to add a header to the attributes:

final delta = fq.Delta();

delta.insert(
          mytext,
          {'header': 1}, // every other attribute I tried works just fine
        );

Any Idea how I could fix this or is there a better way to write styled data to the document which allows me to change things like the font size/header type (1,2,3, etc.) as well?

Thanks in advance.

[johann-gambol]

I have the exact same problem using flutter_quill 6.1.5. Are there any solutions or recommendations?
Thanks!