`populating missing user tags` starts again after updates even though completed tags persist across normal restarts

[CykaTV]

Type

Bug / Performance

Bug description

I have a very large local beatmap library (100k+ beatmaps, ~350 GB) stored on NVMe.

When osu!lazer shows populating missing user tags, the game becomes noticeably less smooth and can stutter outside of gameplay (for example in song select, editor, or general UI navigation).

The main issue is that updates appear to make already-generated user tags become "missing" again.

Once populating missing user tags reaches 100%, I can restart the game normally and the process does not start again.
After a normal relaunch, there are no background tasks running anymore (Tasks in progress: 0), which suggests that completed user tag data is persisted and recognized correctly during normal use.

However, after updating osu!lazer, populating missing user tags starts again from 0 as if those already-populated tags became missing again.

I cannot confirm whether the tags are actually deleted, invalidated, or simply no longer recognized after the update, but from a user perspective updates appear to make previously populated user tags "missing" again.

Restarting from 0 after an interrupted / incomplete run is at least understandable.
Restarting from 0 after an update is the part that seems especially abnormal.

While the process is running, the game becomes less responsive outside of gameplay.
Once the process finishes, performance appears normal again and stays normal across regular restarts, until the next update triggers the process again.

This does not appear to be an HDD-only case, since both the lazer install/data and Songs directory are on NVMe.

Steps to reproduce

1. Have a very large local beatmap library.
2. Launch osu!lazer and let populating missing user tags run until completion.
3. Close and relaunch the game normally.
4. Observe that the process does not start again and there are no background tasks running.
5. Update osu!lazer.
6. Launch the game again.
7. Observe that populating missing user tags starts again from 0 after the update.

Expected behaviour

• Once user tags have been fully populated, they should remain recognized as valid after updating.
• Updating lazer should not make already-populated user tags appear missing again.
• Background user tag population should not noticeably impact responsiveness outside of gameplay.

Actual behaviour

• After updates, populating missing user tags starts again from 0.
• This makes it appear that already-populated user tags become missing again after updating.
• While the process is running, the game becomes less responsive outside of gameplay.
• Once the process finishes, performance appears normal again and stays normal across regular restarts, until the next update triggers the process again.

Version

2026.401.0

Hardware / storage

• Beatmap library: 100k+ beatmaps
• Size: ~350 GB
• Storage: NVMe

Storage / paths

• osu!lazer install/data: D:\osu!lazer
• Songs directory: D:\osu!\Songs
• Both directories are on the same NVMe drive
• Not using HDD / external drive

Additional info

A normal restart after completion does not retrigger the process.
The abnormal behavior is specifically that updates seem to make already-completed user tags "missing" again, which causes the whole populate process to restart and brings back the stutter outside gameplay.

Screenshots or videos

After a populating run is completed + restart :

Version

2026.401.0

Logs

logs after update + complete run + restart
compressed-logs.zip

[CykaTV]

Possibly related:

• Reprocessing of user tags caused major lag spikes #34580
• Song Select Performance very noticably worse than osu!stable #34699
• Going back to Song Select after user tags processing finalized caused 1+ minute freeze. #34583
• Star ratings at song select flicker when background processing is underway #34578

[bdach]

Tags repopulate once per month and updates have nothing to do with it.

My guess is that you weren't aware of the once-per-month thing and therefore you guessed that it was triggered by updates while it was just a complete coincidence.

[CykaTV]

Thanks, that makes sense.

I likely misattributed it to updates because I only noticed it around update time. If this is expected to happen once per month, then the core issue on my side is not the trigger itself, but the impact of the full repopulation on a very large library.

On my setup, when populating missing user tags runs, responsiveness outside gameplay becomes noticeably worse until the process completes. Once it reaches 100%, performance is normal again.

So the actual problem I wanted to report is:

• monthly user tag repopulation appears to cause significant stutter outside gameplay;
• the cost is high enough that it noticeably affects normal non-gameplay use until completion.

If this monthly repopulation is expected behaviour, then maybe the issue should be treated as a performance problem rather than a correctness/update-trigger problem.