Hi Sherly,
I regret for the delay in getting back to you on this issue.
We are glad to inform you that the issue "#10952- Plus symbol is disappeared in MultiColumnTreeview when using CollapseAll() method" has been fixed and the fix for this defect is available in our Development build v6.3.0.33.
Please refer to the below link for development build updates.
http://www.syncfusion.com/downloads/product/build.aspxFor unlock key, Please send an email to
salessupport@syncfusion.com Please let me know if you have any questions.
Regards,
Hema