Some background on the alt+tab-bug we saw at @IEM


During IEM Katowice two matches were marred by a player “alt tabbing” to windows. The problem that caused this was new to our experienced IT-staff.

Throughout the event the cause was researched while a work-around was utilized in which the problem did not reproduce. Today I have sent the findings from the investigation around to other tournament organizers so that they can adjust their operation accordingly if they so choose.

While we are in a state of competition with each other, it is my belief that any problem or issue that could derail an event is a liability to the sport as a whole. Pulling off high level competitions, particularly in CSGO, is complex and can be challenging. Part of the responsibility for any tournament organizer is to do whatever we can do to keep growing and improving esports – for everyone.

An explanation of the bug and its origin is briefly described below for those of you who are interested.

«Alt+tab bug»

Background:

During week one of the Katowice event a windows update caused some minor issues with Dota2. To eliminate the chance of it recurring a new image using Windows Enterprise LTSB was prepared for week 2 which was CSGO week.

Problem description:

At random times players would be ejected from CSGO to Windows, similar to the
effects of hitting alt and tab. They would for half a second see a Windows command
line prompt before reentering CSGO.

Cause:

The problem only occurred with CSGO, and not in any of the other competitions of week 2.
Processes were run to reproduce the issue, which was time consuming in itself.
Further analysis determined why it only occurred with CSGO and no other games:

1. The task that caused the issue is called «Scheduled Retry Scan» and is part of
«Updateorchestrator». This task is not visible by default, which explains why it was difficult to find it.

2. A base task called «Schedule Scan» exists which does not cause the issue. However,
when the internet is blocked (our scenario for CSGO) the task creates «Scheduled Retry Scan»
automatically. It runs, on default, automatically once in a 4-hour period. This explains
why it was difficult to reproduce, and why only affected 2 out of 30 matches.

Problem-solving:

Teams were given an older image that was used at earlier tournament without incident. The task “Schedule Scan” also existed in the older image used (which was based on Windows 10 Pro). Since the bug never happened with that image the working theory is that the problem occurs
exclusively to the Enterprise LTSB version, the one which was implemented for week 2.

The other games using the new image in Katowice had internet enabled, which explains why thy
were not affected. CSGO is the only game with internet restrictions.

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