Error: Undefined array key excludeField in Classes/Service/ObjectSchemaBuilder.php line 165

[t3rookie]

Describe the bug
I have a clean T3 (v12.4.16) with bootstrap_package (v14.0.7) and extension_builder (v12.0.0-beta.2).
This is a composer installation.
When I create a new extension with extension builder, when I filled all fields and have two nodes with one relation I get the following error:
"{"error":"PHP Warning: Undefined array key "excludeField" in vendor/friendsoftypo3/extension-builder/Classes/Service/ObjectSchemaBuilder.php line 165"}

To Reproduce
Steps to reproduce the behavior:

1. I go to extension builder
2. Click on new
3. Fill al fields
4. create two nodes
5. When i want to save, I get error ""{"error":"PHP Warning: Undefined array key "excludeField" in vendor/friendsoftypo3/extension-builder/Classes/Service/ObjectSchemaBuilder.php line 165"}
6. Also the red node delete button on top right corner of the node, does not work.

Expected behavior
is, that extension should save without displaying errors ;-)

TYPO3 Version
T3 (v12.4.16) / composer installation

Extension Builder Version:
extension_builder (v12.0.0-beta.2 )

Browser
Firefox 127.0.2 (64bit) on Win11Pro

Additional context
none

[t3rookie]

I further investigated:

• this error only happens, when there are more than one nodes and if there is a relation between them. Seems to be clear, since there is the option "Is exclude field" only in the relation.
• It does not matter if option "Is exclude field" is on or off
• If there is no relation between nodes, this error will not occur and you can save without errors.

[OliverTempel]

Disable Debug Mode, in particular the option "display errors" as a workaround