Hmmm…
Here’s my typical process…
- open up previously saved .ZTL
- edit and work on .ZTL
- save .ZTL
- keep working (usually)…
- save another version of the .ZTL
- exit ZBrush
- load up a fresh copy of ZBrush
- try to load last version of saved .ZTL…
get *error has been encountered" and ZTL won’t load
- go to previous saved version of .ZTL…
tonight my previously saved version was also corrupt
But other times, the previously saved version (if there was one), loads
More info:
Tonight I started using Svengali’s QuickSave plugin, but this ZTL load error has happen before I installed the plugin.
I generally don’t use the INIT Zbrush option unless I’m working on relatively low poly or unimportant work, as I like to have ZBrush be completey refreshed when I’m working on something important or that has a lot of polys.
The high-poly objects I generally work on are around or under 4million. Lately I’ve been disabling UVs and sometimes get up to around 7-8 million. Performance generally seems ok, but I can’t go higher as I have my poly limit set to 8million and I don’t want my machine to explode. 
More info:
WinXP
2GB RAM
3GHz
Lots of hard drive space, saving to a “network” drive though.
The dragon model I’ve been working on lately, with 6 subds, and 7.6M polys, appears to use up around 900MB on “average”. Though sometimes goes up to 1400MB and uses virtual mem.
Also, I’ve had this issue from a <1M poly model I created in ZB2… just won’t load in ZB3. Same error. I didn’t check to see if it still loads in ZB2.
–
More info:
I believe tonight’s work, my model had 1 layer that I was working on. However, at some point during editing (working at different SubD’s), I lost the ability to access it (select it), regardless of the SubD level I was on…however, all the work I had done was still visible, so I wasn’t terribly concerned…