These:

With the following arc.ini values:

But as I mentioned, so far I fail to unpack it with CIUv205g.

I'm trying to perform a test on the archive directly with FreeArc UI program to see if the archive is actually corrupt or not, this will at least give me an indication where my problem is.

ok, i am tring to compress the game now with ztool with pzlib:m3:r9:c256m i will report back...

I did a lot of attempts with ztool pzlib, never got below 8.99GB final size (2xDVD5+1x300MB+ Disc) for Assetto Corsa.

I even used the ultra preset (pzlib:ultra), further more, because of the game size, it requires a lot of free space or it just end with errors during compression (that's true for both ztool & pZLib3)

after ztool i get 42618mb not alot of zlib detect...
as for pzlib i didn't use it for long time last time i tried to use it i got a lot of crc error's.
try to disable superfetch in windows or use safe mode...

OK...

Anyway, so far, I keep getting when performing test on the archive with FreeArc GUI an error unknown method or parameters in pZLib3:st1

And I did edit the arc.ini in the FreeArc installation folder and added the relevant exe & dll files, trying one more time with a slight change in arc.ini but at the same time trying to re-do my compression without the st1 parameter for pzlib3 and with lzma instead of lzma64.

Hopefully it'll give the same archive result with less decompression problems.

what size you get after pzlib before srep ?

I'm not sure I remember correctly, but I think it was around 24GB with pzlib3, really don't remember about ztool's pzlib, why?

not pzlib that in ztool i meant pzlib v3 seem that ztool does not detected zlib, now i am tring to compress with pzlib v3 instead of ztool and i will try ztool without hif2raw_dll.dll & raw2hif_dll.dll...

OK, Now, I remember that at one point during compression the tempfile was around 11GB too, just not sure if it was before or after srep.

Anyway, let me know what you get.

Also, I'm currently trying the setup again after replacing the pzlib.exe from CIUv205g with the one I used for compression, it's been almost 16 minutes without errors so far.

UPDATE: Nope, same problems, just took longer to happen

There are some games/files, where pzlib3 or ztool have errors from the beginning in compressing. A good and new example is Kingdom Come Deliverance, where some files have some kind of false detection with pzlib, result is either crc error or archive data corrupted in extracting.

Same was a single file for NBA2k18 i guess, where the ratio was over 2000% inflation.

I don't know if it is a generall problem with pzlib or just switches.

Hopefully, that's not the issue here, because that will be really annoying, I'm trying something now, hopefully it will work, if not, well, I guess it'll back to the drawing board.

To be honest, I didn't try to compress it to 1xDVD5 size, that was a shock when I've seen the result, I'll be happy with getting it to work with a size of 2xDVD5 without the extra 300MB+ 3rd disc.

Problem is, so far, only pzlib3 managed to compress the game below 8.99GB size (which result in a 3rd, nearly empty disc)

pzlibv3 and ztool didn't work for me (i mean it did not detect zlib) not decompression error...
i tried to scan different files type (kn5 / ai ) with gfs from razor zlib with levels(slow) no zlib file with dynamic streams option it detect zlib...

@vollachr by any chance did you used msc ?
there almost 9.7gb of dds files...

I'll try and see what works and what not, currently using pZLib3.2.0, will try 3.0.1 maybe.

No, I mean, I tried but I got crashes from MSC, so I gave up on it, other than srep/srep64 & lzma/lzma64 I only tried ztool, pzlib3.2.0 and precomp0.4.3 (which I abandoned mid-way due to way too long times)