Problems with Steam Achievements

There is a problem with Steam Achievements on some of the servers.
The achievements are not counted because steam thinks that cheats are enabled.

You will see something like this in your in-game console:

Code:

Achievements disabled: cheats turned on in this app session.
Achievements disabled, ignoring achievement progress for ACH_KILL_INFECTED_WITH_CHAINSAW

We don't know if a plugin is causing this and which plugin it could be.

Also strange is, that it seems to work sometimes and sometimes not.
E.g. I tested with the chainsaw because I didn't complete this achievement by this time.
Then some kills counted and then all of the sudden I got the error mentioned above in the console.

Here is the current status as observed by us:

L4D	alServ2013 r0r Legacy	no info available, not tested by now
L4D	alServ2014 r0r Legacy	no info available, not tested by now
L4D	alServ2015 Classic	Achievements working
L4D2	alServ2016 Realism	Achievements working
L4D2	alServ2017 Realism	Achievements working
L4D2	alServ2018 Coop	Achievements only working sometimes
L4D2	alServ2019 Coop	Achievements only working sometimes
L4D2	alServ2020 Survival - Realism	no info available, not tested by now
L4D2	alServ2021 GunGameMod	Achievements only working sometimes

So if you are hunting for achievements, only the Realism servers seem to be reliable currently.

I have tested quickly on the "alServ2015 Classic" server.
I could get 2 achievements quite quickly:

• PHARM-ASSIST
  
• CLEAN KILL
  

So it seems to work for this server.
I didn't restart the servers, just connected and played a little.
Or it was just a little time frame were it worked.
The PHARM-ASSIST can be achieved quickly because the bots give the pills back to you.