xvkbd virtual keyboard

Using KDE
If I try the virtual keyboard i get that

X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  12 (X_ConfigureWindow)
  Value in failed request:  0x0
  Serial number of failed request:  1333
  Current serial number in output stream:  1347

How I solv it ?

it seems this was fixed in xvkbd 3.8
See http://t-sato.in.coocan.jp/xvkbd/#changelog

I created a bug report https://bugzilla.opensuse.org/show_bug.cgi?id=1078560