If a testplan with installed plugin is transmitted to another computer with different installed plugins it may happen that the testplan gets overwritten. **Reproduce by:** Create new testplan Insert teststeps Delay/Dialog/Delay/Dialog/Delay Save testplan Open testplan in notepad and replace “DialogStep” with “XXX” + Save Reopen testplan in OpenTap Editor. Now only the Delay teststeps are shown and the log says: 13:07:08.919 Serializer XML Line 11: Unable to locate type ‘OpenTap.Plugins.BasicSteps.LX’. Are you missing a plugin? **Problem:** If user now accidently presses Save or the AutoSave is executed then all missing plugins are lost in the testplan. **Better:** Still show the missing teststeps in the testplan list (greyed out) but do not delete them from testplan if user simply has to install the missing plugin.