Unbelievable. I come back to it a few hours later and it's working. And then not 5 minutes after that it stops working while I'm trying other tools; Scale, Move, Copy,.. doesn't matter. Even selecting with cursor was working while Stretch was not and now that doesn't work either. Bizarre. Nothing has changed (system variables,..). The file has been open the whole time. 

 

PICKADD = 2. No difference with 1 or 0. Also tried changing OSOPTIONS, SELECTCYCLE?,...

 

 So I think at least we can rule out system variables or something I forgot to check or uncheck. Again, this was working fine on old iMac with same OS X. Everything was the same except for the iMac's.

 

Graphics card?

 

iMac (Retina 5K, 27-inch, Late 2015)

3.2 GHz Intel Core i5

24 GB 1867 MHz DDR3

AMD Radeon R9 M380 2048 MB

OS X 10.11.1 (15B42)

>>>Graphics card?

Could be... Not sure.
Have you tried to reset AutoCAD? If no, you can try, but I'd recommend you to backup
~/Library/Application Support/Autodesk/roaming/AutoCAD 2015
and
~/Library/Application Support/Autodesk/local/AutoCAD 2015
folders in order to be able to revert everything back, or at least to restore your customisations for commands and menus from
~/Library/Application Support/Autodesk/roaming/AutoCAD 2015/R20.0/enu/Support
Plot Styles from
~/Library/Application Support/Autodesk/roaming/AutoCAD 2015/R20.0/enu/Plotters/Plot Styles
Templates from
~/Library/Application Support/Autodesk/local/AutoCAD 2015/R20.0/enu/Template
and Content libraries from
~/Library/Application Support/Autodesk/local/AutoCAD 2015/R20.0/enu/Support/ToolPalette

Maxim

 It's working again... And I did not reset ACAD, nor make any changes with system variables or other settings.

 

 I just started up the iMac this morning (after being shut down overnight). Opened AutoCAD LT 2015. Opened same file as before and began using tools; Stretch, Scale, Copy,..etc., even select with cursor. Shift-Click deselect worked every time. Amazing, how it works... and then it doesn't work.. and then it works again.

Does anyone have a thought as to why AutoCAD LT 2015 for Mac is bahaving like this?

Hi,

Please verify that system variable PICKADD=2
You may also try to turn off "lasso selection" feature by setting PICKAUTO=1 or PICKAUTO=2

Maxim

PICKADD was 2, but that's irrelevant because Shift-Deselect would work and then not work w/o any changes to settings.

In the meantime, I've reset AutoCAD LT Mac 2015. It's been working, but it could change again.

Still happening 5 months later.... with AutoCAD LT 2016 for MAC. Same iMac / OS X 10.11.4. 

 

PICKADD = 2

 

Tried changing it to 1 then back to 2, no effect. Minus "-" sign shows above cursor selection box but Shift-Click will not deselect lines/objects. This is very annoying how it'll suddenly start acting up.

It has to do with the Raster Tools Mouse Settings..I had this problem as well and found a solution elsewhere. 

 

https://blogs.rand.com/support/2015/04/autocad-hold-down-shift-to-deselect-does-not-work.html

 

This corrected my issue of not being able to deselect when trying to stretch. Under raster design options, user preferences, mouse settings-uncheck the "Shift+Left click image select". You can find this under the Raster Tools tab in the ribbon and then click the diagonal down arrow in the lower right corner of the "Insert & Write" tool and that will open the AutoCAD Raster Design Options menu.

Welcome to Autodesk Forums!

Hi James,

You are posting in AutoCAD for Mac Forum, but there is no Raster Design on Mac.