[Qgis-user] QGIS not installing properly

[Garth Fletcher]

jessica swan wrote:
> I am wanting to use QGIS for a project,
> but it will not open on my laptop because "this device cannot scan QGIS for
> malware". I have a MacBook Air from 2016 - its software should be updated
> enough to run the QGIS system, but it seems that something is wrong. Could
> I please get some assistance on the issue?

A good problem report should include the OS X version you are using.
I'm guessing that on a 2016 Mac you may be using OS X 10.13 (High Sierra) or possibly 10.14 or 10.15.

By default these, and later versions such as OS X 11, refuse to run programs that are not "officially signed", UNLESS you give them permission to do so.

You only have to give permission once (for a given app); there are 2 ways:
1) control-click on the application and select Open, or
2) right after having plain clicked and gotten the refusal, go to
      Apple > System Preferences > Security & Privacy
    where you may see a message about the rejection and an offer to authorize the rejected app

I always use #1.  As I say, you only have to do it once.  Thereafter single clicking on the app, or one of its files, will start up QGIS.

By the way, while in Security & Privacy / General you will see:
   Allow apps downloaded from:
     ( ) App Store
     (o) App Store and indentified developers
That is usually set for the 2nd choice, but might have been changed to the first
Neither setting allows UNsigned apps, unless you give permission as outlined above for each UNsigned app you want to run.

QGIS runs beautifully on Macs.  I'm using a 2011 Mac mini with OS X 10.13 for making maps with many hundreds of layers and many many GB of rasters, including LIDAR based DEMs with 1.5 foot resolution and orthophotography with 0.5 foot resolution.

Cordially,

-- 
Garth Fletcher