How to remove qt-ap-spi

sudo apt-get --purge remove qt-ap-spi

or use software centre...

Following your suggestion, Terminal result:
is@luis-G41M-Combo:~$ sudo apt-get --purge remove qt-ap-spi
[sudo] password for luis:
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package qt-ap-spi
luis@luis-G41M-Combo:~$

I look everywhere for qt-ap-spi
 but cant find it.
This come about from Thread #257100 which I never had a answer, I was advised to upgrade to Librecad 2.0.6. I did this but the gremlin continued, then was advised to
sudo apt-get --purge remove qt-ap-spi
. After I tried on Terminal “librecad” the result was this:
 Open Terminal enter “librecad” it open with error in terminal but I carry on on saving file it close again sending result of Terminal it might help.
 luis@luis-G41M-Combo:~$ librecad
RS_DEBUG::setLevel(3)
RS_DEBUG: Critical
RS_DEBUG: Errors
RS_DEBUG: Warnings
Got bus address: "unix:abstract=/tmp/dbus-O7dlqekdI5,guid=a610166aaed5b8adc8e17e040000001d"
Connected to accessibility bus at: "unix:abstract=/tmp/dbus-O7dlqekdI5,guid=a610166aaed5b8adc8e17e040000001d"
Registered DEC: true
Registered event listener change listener: true
QSpiAccessible::accessibleEvent not handled: "8008" obj: QObject(0x0) " invalid interface!"
QSpiAccessible::accessibleEvent not handled: "8008" obj: QSidebar(0xb7de550, name = "sidebar") "sidebar"
FIXME: handle dialog start.
QSpiAccessible::accessibleEvent not handled: "8008" obj: QObject(0x0) " invalid interface!"
Interface is not valid
ASSERT failure in : "Got an update for an invalid inteface. Investigate this.", file atspiadaptor.cpp, line 899
Aborted (core dumped)
luis@luis-G41M-Combo:~$

As I have another HD with Ubuntu 14.04 install LibreCad and tried the same file save and it work
perfectly.
I hope this will help
Please can you help to fix this.

I cannot find any information about an Ubuntu package "qt-ap-spi". Maybe this is a typo error and should read "qt-at-spi"?

In https://bugs.launchpad.net/ubuntu/+source/qt-at-spi/+bug/998012 the instructions is to remove qt-at-spi not the inexistent qt-ap-spi.

Try

sudo apt-get purge qt-at-spi

Apologize for the qt-ap-spi.
Following your suggestion I can now save the files it is working properly.
Thank you.

Thanks actionparsnip, that solved my question.