When League of Legends interrupts a player with League Critical Error Crash, the useful question is not whether a reinstall is possible. It is which part of the session failed and which test will prove it. League displays A Critical Error Has Occurred or closes at match start The workflow below separates an account, content, network or local device problem before recommending more disruptive steps.
Recognize the failure before changing anything
Typical sign: League displays A Critical Error Has Occurred or closes at match start Write down the complete on-screen text rather than searching on a shortened number alone. If the issue happens online, record the platform and selected region; if it is tied to a saved game or mod, note the save and content versions. These details prevent a reasonable-sounding fix for another game build from being applied in the wrong place.
What the symptom may indicate: Conflicting overlays, drivers or damaged local data can affect the game process This is a diagnostic hypothesis, not an automatic root-cause verdict. A problem occurring across several devices at the same time often needs a different response from one that reproduces on a single PC. Compare those scopes before making changes.
Protect your account, installs and progress
Important: Do not download random DLL files, disable device security or increase voltage to work around a crash. Record driver version and any non-default clocks before testing. Return one graphics or overlay setting to stock per trial. A crash dialog cannot by itself prove a defective GPU. For a managed device or a shared game account, get approval from the owner before changing network, privacy or security settings.
Step-by-Step Troubleshooting
Use the safe checks first. Advanced steps are for evidence-based investigation after initial tests fail.
Capture the exact error code and game build
Reproduce the reported symptom once: League displays A Critical Error Has Occurred or closes at match start. Write down the entire message, game build, platform, launcher and time of failure. Note whether it occurs during launch, account login, matchmaking, loading or gameplay; those are different components. If personal data appears in logs or screenshots, redact it before sharing. A repeatable baseline helps determine whether later changes actually fix the problem.
Separate service status from local failure
The main possibilities are: Conflicting overlays, drivers or damaged local data can affect the game process Check official League of Legends service or patch notices before modifying the computer or console. Compare one unaffected feature, such as offline play versus online access, or a stock map versus a modded one. If the publisher confirms an outage, wait for recovery rather than repeatedly resetting the device.
Run the first game-specific check
Disable third-party overlays for one controlled launch and record when the crash happens Perform this as a single, reversible test and record the outcome. If the issue changes, capture the new message before moving on. For a launcher update, wait for all downloads to finish; for account errors, confirm ownership without sharing credentials. Restore unrelated application settings if the test makes no difference.
Try a second controlled comparison
Update through the supported launcher and test a practice match at default display settings Keep the same account, region and game build unless this step explicitly checks one of those values. Compare the passing and failing cases rather than applying every popular internet fix. Return one graphics or overlay setting to stock per trial. A crash dialog cannot by itself prove a defective GPU. Stop if a repair asks you to sacrifice the only working save, purchased-content license or account access.
Read the crash report and graphics event
Use Windows Reliability Monitor or the publisher crash report to identify the faulting component and crash timestamp. Compare with display-driver reset events, recent GPU changes and overlays. Treat one crash signature as a lead, not proof of failed hardware.
Apply the supported advanced path
Check crash logs and driver event messages; escalate with a reproducible case rather than deleting account files This is only justified after the two lower-risk comparisons; if the evidence points to publisher services, stop local tinkering and monitor the official incident. Back up settings first and reverse any diagnostic changes that do not help.
Distinguish a new error from the original
Repeat the exact failing action in League of Legends. If a new error appears, note whether login, launcher verification, map loading or network negotiation progressed beyond its previous point. That suggests a new boundary to diagnose, not permission to reinstall or erase everything. Keep the system version and account constant across comparisons.
Confirm the repair and decide when to escalate
Success condition: A practice match runs through loading and several minutes of gameplay. Re-test after a clean restart and one additional session where safe. If the problem persists, send publisher support the exact code, game build, affected platform, time zone, reproduction steps and redacted logs. Do not download random DLL files, disable device security or increase voltage to work around a crash. Record driver version and any non-default clocks before testing.
Read the results: what each observation means
| Observation | Check | What to do next |
|---|---|---|
| The original error reproduces | League displays A Critical Error Has Occurred or closes at match start | Preserve the exact message and triggering action; confirm whether it is local or widespread. |
| First low-risk test changes the outcome | Disable third-party overlays for one controlled launch and record when the crash happens | The component changed by the test is a useful lead, not final proof of the root cause. |
| Second controlled test changes the outcome | Update through the supported launcher and test a practice match at default display settings | Compare the new and old result while keeping the account and software version consistent. |
| The issue persists after safe checks | Check crash logs and driver event messages; escalate with a reproducible case rather than deleting account files | Collect targeted logs and use the documented publisher workflow, or escalate with clear evidence. |
Why a generic repair can fail
This problem has a narrow trigger: League displays A Critical Error Has Occurred or closes at match start A suggestion to reinstall every launcher, reset the router, or disable anti-cheat would not establish the cause. Instead, test Disable third-party overlays for one controlled launch and record when the crash happens first, then Update through the supported launcher and test a practice match at default display settings. Each result should answer a concrete question about the source of the failure.
If those tests do not isolate the cause, the deeper path is to Check crash logs and driver event messages; escalate with a reproducible case rather than deleting account files. Preserve the original failure timestamp and the exact game build. Online codes and UI wording can change after updates, so distinguish supported vendor explanations from community guesses before publishing a definitive meaning.
Verify that the solution worked
Pass condition: A practice match runs through loading and several minutes of gameplay Repeat the original action—not a related activity—after reopening the game. For a connection failure, attempt another ordinary session once; for a save or content problem, verify a safe copy can be loaded again. If the same message returns, document which stage failed and follow the advanced route without discarding earlier evidence.
Solution Checklist
Further reading: official game and platform support
Start with Riot Games League Support for currently supported procedures and service advisories. Publisher support pages can change by game version, platform and region. Verify that the guidance covers your exact environment before performing a privileged, destructive or security-related operation.
If the display text or numeric suffix differs from the wording here, treat it as a separate variant until the publisher documentation or a diagnostic log establishes the mapping. Do not infer a hardware or account sanction solely from a community nickname for an error.