Tree serializer lost userdata node when node is expanded

Hi there,

When I serialize my tree with data coming from xml source, all userdata per node are present.
I expand one node and serialize the tree and the expanded userdata node are no more there.

Before:

  <tree id="0">
  <item text="system 5-25 F15" id="1552559652475_-4946621593608994990">
   <userdata id="2cor11694"/>
    <userdata item="9902-03-0012"/>

after expanding:

  <tree id="0">
  <item text="system 5-25 F15" id="1552559652475_-4946621593608994990">
  <item text="Atomizer, Assembly F-15 w/motor GV00 NPS S00" 

dhtmlxSuite professional version is dhtmlxSuite is 4.6.1

Looks like there is the same issue with dhtmlxSuite_v51_pro_eval

Any help?

Pleas,e make sure that you’ve enabled the first parameter of the setSerializationLevel() method:
https://docs.dhtmlx.com/api__dhtmlxtree_setserializationlevel.html
If the problem still occurs for you please, provide any kind of code snippet, or a complete demo, so the problem can be reproduced locally.