Save and Load Error

[cast-hdmu]

FancyTree Version 2.38.3
jQuery: 3.7.1
Browser: On any Browser

If there are many branches and these remain open, and the page refreshes, also via F5, the error occurs.
Apparently it is an error in the:
$("#tree").fancytree({
extensions: ["table", "persist"],

The error is in the current version as well as in the older version which is attached.
Then there is a small box under the header

See attachment

Fancytree_Error.zip