Unfortunately, the only way to fix this problem is to uninstall the program and then install it again. The memory access violation error pops up due to a corrupt file and there is no way to fix it. To recover your data, you can try to move the program's backup file before you uninstall it. The default path for this file is : C:\ Program Files \ClickTray Calendar \Benutzer \BOrdner0 \Kopie. Move all the files to another location, uninstall the program and move the files back after you installed a new version of the application. You can do this only if you backed up your data. If not, there is nothing that you can do to recover the address book.