Crash Issue Fix Report - 18 July

Due to the recent increase in crash incidents, which have significantly impacted your gaming experience, we have swiftly investigated the issues and released multiple updates over the past few days. The issue is nearly resolved, but we are continuing to monitor it. We understand that we cannot undo the issues that have already occurred, but we hope this report can share some information and demonstrate our commitment to the player experience.

Crash Stat:

Versions before July 12: Average crash rate - 0% Versions from July 12 to July 14: Average crash rate - 18.4% Versions from July 14 to July 16: Average crash rate - 32.1% Version from July 17: Average crash rate - 14.1% Version from July 18: Average crash rate - 0.025%

Based on anonymous cloud log reports, the recent crashes are caused by the following two issues:

Issue 1:

In simple terms:

This issue is caused by changes in the total number of buildings in the scene, particularly when reduced, leading to an out-of-bounds array query in the C++ code for querying buildings, resulting in a crash.

The Boring Part:

When enemies patrol, they check for nearby heroes or buildings. If there are both buildings and heroes nearby, they prioritize attacking heroes; otherwise, they attack buildings. When the AI patrol system retrieves the building list, a change in the list during this process causes a null pointer issue in C++, leading to an out-of-bounds array query and a crash.

The occurrence probability of this issue is positively correlated with device performance. Due to the high performance of our development machines, we did not replicate the issue in our lab environment, delaying the fix.

Solution:

We have modified the code execution order and added boundary and pointer checks. Based on cloud logs, the patch released on July 18 has significantly reduced the occurrence of this issue, with no further occurrences reported. We are continuously monitoring the issue and will release further fix reports as needed.

Issue 2:

In simple terms:

This issue occurs when the turret's material is changed during tower construction, leading to a crash due to an incorrect material replacement.

The Boring Part:

During tower construction, the turret's material is changed and a material animation is played. During this process, a low-level error might cause an attempt to access a non-existent material, resulting in the failure of setting the instance material or shader material parameters, leading to an OS crash.

Solution:

This issue has a relatively low occurrence probability. We have added boundary and pointer checks. Based on cloud logs, this issue has not reoccurred, but we will continue to monitor it.

Our team has been working at full speed over the past few days to resolve these severe crashes. We apologize for the negative experience caused. If you no longer encounter crash issues after updating to the latest version, please feel free to let others know. If the problem persists, please continue to inform us. Thank you for your support and attention.