Microsoft’s August 2025 Patch Tuesday rollout brought an important Defender security update for new Windows 11 and 10 ISO image installations to protect against threats like Lumma stealer malware. This update is important for new Windows ISO installations as the installation image may contain old, outdated malware definitions and software binaries. Updating Defender ensures that the fresh installs are protected from the latest threats and can also provide improved performance benefits.
As part of the same rollout, Microsoft also released the Windows 11 24H2 cumulative package KB5063878 that was meant to improve security and system stability. However, soon after deployment, some users are reporting issues like: solid-state drive (SSD) failures, data corruption risks, and unexplained crashes under heavy workloads.
In this article, let’s decode the problem and how to identify it, and ultimately, ways to safeguard your files.
Early Problems with KB5063878
Right after Microsoft released the KB5063878 update, many people couldn’t install it. The update failed with an error code 0x80240069, which Microsoft later admitted was a problem on their side and then fixed.
Once the installation issue was fixed, another issue showed up when people tried to install the update: some users started having trouble with their storage drives (SSDs).
How Users Discovered the Problem
Community testers began investigating these reports. A Japanese tester, NichePCGamer, ran big tests on 21 different SSDs to see what was happening and discovered a repeated failure pattern:
- Copy a large game folder to the SSD.
- Save a 62 GB archive full of video files on the same SSD.
- Unzip or extract that archive on the same device.
During this process, many SSDs stopped responding once about 50 GB of data had been written continuously. In some cases, drives suddenly disappear and their SMART (Self-Monitoring, Analysis and Reporting Technology) data becomes unreadable by Windows.
The problem seemed to affect certain SSD models, especially those using Phison controllers and DRAM-less models. Tests found the issue often occurs on some NVMe SSDs, and even HDDs are more than60% full, and about 50 GB of data is written at once.
Warning for Windows 11 Users (Update KB5063878)
The August 2025 Windows 11 update (KB5063878) may cause the following problems with SSDs and possibly HDDs, as per the report:
- Drives can disappear or stop working during large file transfers (around 50GB+).
- Folders may still show, but files often can’t be opened.
- Restarting the PC may temporarily store the drive, but the issue reoccurs under the same workload.
- Disabling features like HMB doesn’t help; testers suspect a Windows memory leak during buffered writes.
- There is a real risk of data loss if users keep pushing the SSD under heavy loads.
Can You Lose Data After Updating?
Yes, you can lose data after installing update KB5063878, especially if you perform a large file transfer process. In that case, your drive might suddenly disappear, and files could get damaged.
For now, everyday tasks like browsing or editing small files are generally safe after installing KB5063878, but while performing heavy workloads that include transferring games, video archives, or backups, there’s a risk of losing data.
If you’ve already lost files due to this issue, use professional data recovery software like Stellar Data Recovery Professional to recover inaccessible or deleted data.
Microsoft Confirms Another Flaw: Reset and Recovery Failures
While reports of SSD failures were spreading, Microsoft admitted another flaw: Reset and recovery operations may fail on some Windows versions.
The issue appeared after installing August 2025 security update specifically KB5063875 on Windows 10 and 11 client versions (but not Windows 11 24H2 or server OS).
This issue appeared when users tried to perform on or more of the following recovery options:
Microsoft has addressed the issue and quickly released an out-of-band (OOB) update to fix it, advising administrators to install the OOB version instead of the original August 2025 patch.
A Microsoft spokesperson said: “We’re aware of these reports and are investigating with our partners.”
The company also apologized for the any inconvenience and confusion the issue has caused.
What Users Should Do
For now, continue to investigate the storage failures, the reset/recovery bug has already been addressed via the OOB update. Until formal guidance is published, users are advised to take precautions:
If you have installed KB5063878, here’s what you should do:
- Back up important files immediately to an external drive or cloud storage.
- Avoid very large file transfers (50GB or more) on systems updated to KB5063878.
- Be careful if your SSD is over 60% full or uses a Phison controller, as these drives are most at risk.
- Remember: rebooting the system is only a temporary fix and does not prevent the issue from returning.
- Install the OOB update if you’re affected by reset/recovery failures.
- Watch for official updates from Microsoft and your SSD vendor for SSD-specific firmware, driver, or OS fixes.
- Consider using reliable data recovery software if files have already been lost.
Final Thoughts
The Microsoft’s August 2025 update, though expected to strengthen security, has unexpectedly raised serious risks for storage stability and reset/recovery glitches. As Microsoft is working on fixing the issue, in the meantime, users should pause large transfers and maintain regular backups of their important data until and keep systems updated with the latest OOB patches.
