Beq Janus commented at 2018-08-17T18:36:03Z

To add a little colour to Willow's note. MAINT-8258 is the most likely candidate but it is far from obvious how it is being triggered, here is my guess so far, feel free to shoot it full of holes.

#1 there is a latent bug in the sculpt() method
As the image shows the comment and the code are not aligned, as we cannot see the change that it references, it is impossible to know whether it is the comment that is wrong or the code.
#2 The implication of the code as it stands today is that any sculpt that is shown at LOD1 gets its mesh data zapped to empty. The reason I am dithering over this is I am far from convinced that a sim surround would ever render at LOD1 in the first place so this is quite possibly a red herring (It might still be a valid bug though.)

Willow Wilder commented at 2018-08-17T19:51:07Z

I went to Testylvania to try and rez the sim surround added at that location.
http://maps.secondlife.com/secondlife/Testylvania%20Sandbox/179/21/22

Snapshot FS Nightly (1) At 200m and LOD 2.00, was able to rez the Big Baby, but not the sim surround. Not able to rez it by using any camming "tricks".

Snapshot SL Viewer (2) At 200m same results as (1) above.

Snapshot FS Nightly (3) Ramped DD to 1024m and LOD 4.00 and sim surround appeared. Was able to drop DD to 176m and LOD to 2.00 before Big Baby disappeared.

Alexa Linden commented at 2018-08-17T20:40:25Z

leave the baby out of this! he's doing no harm :D

Alexa Linden commented at 2018-08-17T20:44:29Z

I can repro this bug. both at the orginal location and testy.

Willow Wilder commented at 2018-08-18T03:30:47Z

I'm available for babysitting and spoiling. Have experience with rubber duckies and towels. (y)

AndreyK ProductEngine commented at 2018-08-28T17:43:37Z

I tried reverting MAINT-8258 and I still see land at Testylvania location as flat surface, so it doesn't seem to be the case.
Checking out Love Me Render changes.

P.S.
@BeQ Janus
Lod 0 is marked as impostor, so I'm not sure if it is valid as 'lowest lod', that comparison is likely to be correct as is.

AndreyK ProductEngine commented at 2018-09-04T15:44:19Z, updated at 2018-09-04T15:44:46Z

Please try testing at http://wiki.secondlife.com/wiki/Release_Notes/Second_Life_Release/5.1.9.519162 (latest maintenance build)
I pulled to my local branch today and suddenly there is a mountain... but may be a glich my side or something with settings (but launching 5.1.7 displays no mountain).

Whirly Fizzle commented at 2018-09-11T08:58:14Z

Confirmed that this does seem to be fixed on the Maint-RC.
I tested on https://wiki.secondlife.com/wiki/Release_Notes/Second_Life_Release/5.1.9.519162

Willow Wilder commented at 2018-09-15T15:06:17Z, updated at 2018-09-15T15:06:46Z

I'm afraid I'm not seeing much of a difference using Second Life Release 5.1.9.519298 (64bit)

I did see a small hint of a sim surround when I first moved to the region edge at Testy (DD 128m) but I still had to ramp DD 512m and cam around and finally edit the sim surround before I was able to render anything further.  https://prnt.sc/kuqiwb 

I've requested one of the other reporters with this issue to also test on the MAINT-RC viewer and post results. 

AndreyK ProductEngine commented at 2018-09-15T17:38:48Z

Ok, thanks for the info. If possible, please attach logs, just in case.

Willow Wilder commented at 2018-09-16T01:24:49Z

SecondLife.log attached as requested. 

Whirly Fizzle commented at 2018-09-16T01:40:41Z, updated at 2018-09-16T01:50:30Z

Has something changed with the log formatting on 5.1.9.519298?
It's broken in all my log readers...
eg) https://prnt.sc/kuw9b0 from Willow's log

Edit to add: https://bitbucket.org/lindenlab/viewer-bear/commits/7a2c91f8f8a59287027a8b89fe3fd161cb773806
I guess it's this?
That makes logs really hard to read. I'll file a JIRA for it later.
Carry on lol.

AndreyK ProductEngine commented at 2018-09-16T11:37:52Z, updated at 2018-09-16T11:40:11Z

SecondLife.log attached as requested.
Thanks.

I guess it's this?
Yes
Quote: "The point is to make parsing, combining logs, and filtering much easier because every line will start with the same fixed format."
As I understand, we are supposed to use some kind of transform script to make it readable again (and probably to use some kind of alternate console launcher for 'live' logging)

Whirly Fizzle commented at 2018-09-16T15:54:09Z

Thanks.
I filed an issue for the wonky log formatting: BUG-225480