I can replicate a crash on my IMac, create a sphere and make polymesh and delete 2/3 of the mesh.
Go to edge loops and delete loops and align loops crashed the program in both 32 and 64 bit version. 
Not good, trying to do a tutorial and canāt get past the delete loops.
Pixologic, is this a known issue and is there a workaround please, anyone. ?
I canāt replicate this on Win 7. Perhaps you could be more specific in the steps you were using to make this happen, maybe with a picture?
Parametric spheres do have geometry that is problematic for some operations however, because the poles are actually unwelded. This can cause unintended behavior in some situations. It can sometimes be helpful to first weld the points of a parametric sphere (tool> Geometry> Modify Toplogy> weld points), or to re-mesh it entirely before performing operations on it.
Iām pretty sure the windows version is ok, the tutorials are run on a windows system. But if you like Iāll let you have the ZTL file and see if you can just use the delete loops.
RH
I tried welding the points up from and no difference sadly.
Make a polyshere, weld points as you suggest, Hide a centre section all way through sphere.
from here go to edge loops and select displace amount =1 and select edge loop to get this.
and in the same panel select remove loops with any angle and as I hit the button my program crashes. But I should get the other curved sides flattened according to the video tutorials.
RH
I canāt be certain Iām following the steps correctly, but when I follow along to the best of my understanding, I get this:
There are other ways to go about making this shape, but of course that doesnāt help you as youāre trying to follow a tutorial. Perhaps if I were to follow the tutorial in question directly.
In any event, Iām not disputing you may have an issue on your system configuration. If it would be helpful to you to try to recreate the crash on another system, Iād be happy to take a look at the file in question. If you are confident you have a bug, however, the Q&T boards are probably not the best place to report it. The file and report should probably go to Support along with system info.
The image you have ended up with is correct to the point of having a second tapered area moving towards the point.
Submitted a support ticket and ZTL file. Lets see what happens.
RH
Well, I didnāt delete the mid section because you only specified that you hid it in your instructions.
As far as where to report a reproducible bug, I would personally make a support ticket for it with a problematic file and system info, because anecdotal reports are only so helpful in bug finding, and because the developers donāt always see everything on these boards. They may not be able to do anything about it other than forward it. But Iām just another user, not a Pixo rep, and I may not be giving you the correct policy.
I understand , it doesnāt matter if you leave it intact, separated or any other form they all crash.
iāve submitted my ticked, but even if you canāt replicate, no matter , if someone here has a 2008 IMac, maybe they can or maybe see whats happening easier than I do.
Oh well, canāt put ztl files here, so ill make a drop box tomorrow , Iām off to bed lol.
Thanks ok. Iāll PM you tomorrow.
Crashes 64bit Mac OS X Lion as well (not going to bother trying 32bit).
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: 0x000000000000000d, 0x0000000000000000
Thread 0 Crashed
Dispatch queue: com.apple.main-thread
0 com.pixologic.zbrush 0x000000010b220025 AMeshEditOptimizePattern_OptimizeEdgeLoops(float, bool, bool, bool, bool, float, bool) + 1157
1 com.pixologic.zbrush 0x00000001090a0f6e AToolMashNotifyControlChanged(int, unsigned short, AObj*) + 81726
2 ??? 0x446b000045196000 0 + 4930034218246430720
Also tried using āAlign loopsā instead of Delete Loops ā¦ same result.
Iām not sure what the objective of the tutorial is (why the need to delete non-essential loops?)
Thats the one, sorry to hear yours crashed too, but at least its not me lol. Iāll keep posting to this thread with updates from Pixologic about the ticket posting.
Thanks for confirmation Thor.
I think the point of deleting the loops is to show it there, Iām very new to ZB and this tutorial from DT is showing all the tools available and how to use ZB.
RH
I was able to both delete and align loops on the open semisphere without issue in Win 7 x64, in the file you sent me Rachel. Since Thor can replicate, it looks like an OSX issue as you surmised.
I know youāre trying to follow a tutorial, but if you need tips on alternative ways to do what youāre trying to do, just let us know. You could, for instance, just delete the loops with the ZModeler Edge> Delete > loop, or Edge > Insert > Single loop while holding down ALT.
Many thanks Spyndel and Thor.
Iāve received an email this morning from Pixologic. They too have managed to replicate the crash and this has been forwarded to the Devās.
Thanks again Spyndel, your idea is a big help and also was included in the email form Pixologic lol.
Thanks Guys.
RAH.
Has there been any more word from the Devs on this? I encountered this bug trying Delete Loops.
MacBook Pro running 10.11.5 on 4R7 P3. Iāll submit a ticket as well.