This is Clipman 1.2.3 With very large lists of 500 items, the panel button does not open the list anymore on click. The button is pressed and does not return, the only way to return is pressing ESC. clipman still works by setting an application shortcut for xfce4-popup-clipman and enabling "Position menu at mouse pointer" -> therefore not a blocker for me anymore after finding that out, but severity:critical. Clearing the long list by the entry at the end of the list makes the icon work again and the list is opening on press.
=> severity changed to normal since it's not a crasher but a usability issue
Clipman has 2 ways of using: Started at startup and using from notification bar, or explicitly adding to the panel as widget (while disabling the start at startup for not having 2 instances). I prefer the 2nd method for being able to place the icon somewhere and not in the notification bar. This issue only happens with the 2nd method and the panel widget. Opening by shortcut still works.
Still an issue with panel applet in Xubuntu Precise, using Xfce 4.10. Increased the entry size from 10 to 125. Clicking, appears to pop-up offscreen instead of pop-down visible. Reduced the size to 10 entries and it continued having the issue. Attempted to find a command to clear the history through the terminal: ran xfce4-popup-clipman, and the history appeared as normal. Tried to recreate the issue by increasing the entry size and couldn't.
fixed in git commit eaa252ea4308490b9c6fa7a518eaed860dbfd989 thanks for the report!