Sorry for the inconvenience caused because of the Magnetic lasso tool crashing Photoshop after the recent 19.1 version.
A workaround is to Change the cursor preference to standard and that will prevent the crash. Navigate to the Preferences>Cursors menu as shown below.
We are aware of this issue and are working on it. I'd also recommend you to take a look at this discussion Photoshop CC 19.1: Crashes when using Magnetic Lasso Tool | Photoshop Family Customer Community as this is community is monitored by our Engineers actively,
Adobe Photoshop CC 2018
24-Jan-18 8:22 PM
Faulting Application Path: C:\Program Files\Adobe\Adobe Photoshop CC 2018\Photoshop.exe
Problem Event Name: APPCRASH
Application Name: Photoshop.exe
Application Version: 220.127.116.11906
Application Timestamp: 5a5dba9e
Fault Module Name: StackHash_8575
Fault Module Version: 10.0.16299.192
Fault Module Timestamp: 6dead514
Exception Code: c0000374
Exception Offset: PCH_54_FROM_ntdll+0x00000000000A09C4
OS Version: 10.0.16218.104.22.168.256.48
Locale ID: 1033
Additional Information 1: 8575
Additional Information 2: 8575937f7892f89135277a7905b44243
Additional Information 3: 4dc4
Additional Information 4: 4dc4aa7c751564f6e80a68dc97fabdfa
Extra information about the problem
Bucket ID: e3a6a6e906e55e6065d980d4563efdfc (1574431194211089916)
2 people found this helpful
Caps Lock sets the cursor to Precise, so that will encounter the issue as well
Having the same exact issue with the pen tool, tried the cursor change... Didn't work. Tried this on 2 different computers (one at work and one at home).
I have updated photoshop cc 2018 and immediately it crashes when using the magnetic lasso tool which sucks because this is the most used tool for me. I can't use the program at this time and have to use Coreldraw, have no time to figure what is wrong or reload. Not good that Adobe releases a program update without making sure it works 100%. If I dont check my work and send it to the client I lose my job period!!
Is there a fix? I need precise tooling for what I'm doing.
I reverted back to version 19.0 and all of my problems have stopped. Until they release a patch or fix I will continue to use 19.0 so I can keep my projects moving forward.
To install a later version of Photoshop open you Creative Cloud app and click the down arrow on the right side of the blue button for Photoshop
Then pick "Other Versions" and install 19.0. It took care of all my issues and I am able to use all my tools without any problems. It is not a perfect fix, but it will get you working again!!!
Please update Photoshop to 19.1.1 version, which includes the fix for "Photoshop CC 2018 crashes while using Pen/Magnetic Lasso Tool".
Also, refer the list of other fixed issues in 19.1.1 release: Fixed issues in Adobe Photoshop CC
To update Photoshop CC to 19.1.1, click "Update" in the Creative Cloud desktop app next to Photoshop CC.
I found everything froze after using the magnetic tool leaving me no option but to crash my mac and start over. (All the commands were were greyed out. However, having read all the answers in this thread, I clicked on Adobe Ps Preferences which was pretty much the only thing not greyed out. I was going to see if I could change the cursor pref to standard as suggested, but it was already marked as standard. HOWEVER, when I went back into my page, by dint of just going into Preferences, it seemed to un-grey all the commands so I could deselect the magnetic tool. What a palava but it did work. I just won't use this tool again! I should add my version is 20.0.0 so clearly this fault is still happening but hope the above offers a getaround.