steps to reproduce

1. run ZSS with ZK 8.0.2.1
2. check css class name with chrome dev tool

actual result

some CSS class names contains undefined:

• add sheet button{{class="zstbtn-undefined ...}}
• toolbar button: zstbtn-undefined zstbtn z-toolbarbutton
• menupopup / mentuitem

  <ul class="z-menupopup-content" id="_z_29-cave"><li id="_z_33" class="zsmenuitem-undefined z-menuitem">...</li></ul>
  

expected result

like the previous version, with correct CSS class name

debug info

• there is no such issue running with 7.0.5.2, 7.0.8, and it happens since 8.0.0. But the "add sheet" still works.
• this issue makes ss.disableUserAction(AuxAction.ADD_SHEET, true); not work.

workaround

• alternative selector jq('a[title="Add sheet"]')