The "Scan error: thread 0" in Cheat Engine often occurs when the user attempts a scan without providing any input or when the software encounters a low-level access issue
. While "thread 0" sounds like a deep system crash, it is usually a simple fix related to your input settings or administrative permissions. Top Solutions for "Thread 0: Please Fill Something In" If you see the specific message "Please fill something in"
along with the thread 0 error, it means you clicked "New Scan" or "Next Scan" while the value input box was empty. Enter a Value:
Type the number (e.g., 100) you are looking for into the value box before clicking scan. Check Scan Type:
If you don't know the exact value, change the "Scan Type" to "Unknown initial value" instead of leaving the box blank.
Troubleshooting "Thread 0: Access Violation" or "Stream Read"
If the error occurs even with a value filled in, it typically points to a lack of system permissions or background interference: Run as Administrator: Right-click the Cheat Engine shortcut and select "Run as Administrator" . This is the most common fix for access violation errors. Antivirus Interference:
Some antivirus software (like Comodo or Windows Defender) blocks Cheat Engine from reading another program's memory. Try temporarily disabling your firewall or adding Cheat Engine as an exception. Switch to 64-bit: If you are using the 32-bit version ( cheatengine-i386.exe ), try using the 64-bit executable ( cheatengine-x86_64.exe
) to match your modern operating system and target application. Change Temp Folder:
If you get a "Stream read error," Cheat Engine may be struggling to save scan files. Go to Settings > Scan Settings The "Scan error: thread 0" in Cheat Engine
and change the "Custom path" for temporary files to a folder with full permissions, like your Desktop. Enable MEM_MAPPED: Settings > Scan Settings , check the box for "MEM_MAPPED"
. This can help Cheat Engine see memory that is usually hidden or protected. Quick Fix Checklist View topic - Scan error:thread 0:Stream read error
The "Scan error: thread 0" message in Cheat Engine typically occurs when the software cannot correctly access or interpret the target application's memory. This error is often tied to architectural mismatches or specific scan settings that prevent the scanner threads from executing properly. Common Causes and Solutions Architecture Mismatch (32-bit vs. 64-bit)
Running a 32-bit version of Cheat Engine (cheatengine-i386.exe) on a 64-bit process often triggers thread errors or "no readable memory found".
Fix: Ensure you are using the 64-bit executable (cheatengine-x86_64.exe) found in the installation folder. Invalid Value Input
Entering values that do not match the selected Value Type (e.g., entering text while scanning for 4-byte integers) can cause thread 0 to report an "invalid value" error.
Fix: Double-check that your input matches the expected format (Hex, Decimal, Float, etc.). Processor Affinity Issues
Sometimes Cheat Engine struggles with multi-core synchronization during a scan.
Fix: Open Task Manager, right-click Cheat Engine under the Details tab, select Set affinity, and try restricting it to only one or two CPU cores. Memory Scan Settings Note: Cheat Engine is intended for legal uses
If the memory region is protected or not marked as "writable," a default scan may fail to find results or error out.
Fix: Go to Settings -> Scan Settings and ensure MEM_MAPPED is enabled. You can also try unchecking the "Writable" box if you are searching for static code bytes. File Path and Permissions
Errors during pointer scans often occur if the save path for scan results contains non-ASCII characters (like accented letters) or if the program lacks permission to write to that folder.
Fix: Save scan results to a simple path like C:\CE_Scans\ and run Cheat Engine as an Administrator. Troubleshooting "0 Results" After a Scan
If the scan completes without an error but returns 0 results, consider these adjustments:
Value Type: Change the Value Type from "4 Bytes" to "All" to catch values stored as Doubles or Floats.
Scan Type: Use "Unknown initial value" and subsequent "Increased/Decreased value" scans for encrypted or obfuscated values that don't match the on-screen number.
Big Endian: If using an emulator like ZSNES, you may need to use Big Endian value types.
Are you seeing this error with a specific game or while following a particular tutorial? View topic - Scan Error - Cheat Engine Forum Enter a valid number (e.g.
Note: Cheat Engine is intended for legal uses like game modding, debugging your own software, or memory analysis. Only use it on programs you own or have permission to modify.
If you get this error from a Lua script:
-- ❌ Wrong: memrec.OnClick = function() startScan() -- missing parameter end-- ✅ Correct for unknown scan: memrec.OnClick = function() startScan(nil, nil, nil, nil, nil, nil, "Unknown initial value") end
-- ✅ Correct for value scan: memrec.OnClick = function() startScan(100, vtAuto, nil, nil, nil, nil, "Exact value") end
cheatengine-settings.ini (in %APPDATA%\Cheat Engine\)| Cause | Explanation | Fix | |-------|-------------|-----| | Anti-cheat software | EAC, BattlEye, Vanguard block CE | Use kernel-mode debugging (advanced), or avoid protected games. | | Scanning too wide range | Scanning all memory (e.g., All Memory region) triggers errors | Change scan type to only the process’s main module (e.g., .exe/.text section) | | Memory type mismatch | Scanning for Float but the value is Double/4-byte | Correct the Value Type in Scan Settings | | Fast Scan misconfiguration | “Also scan read-only memory” unchecked when needed | Enable “Also scan read-only memory” | | Process has high integrity level | Running as admin vs. game as user | Run both Cheat Engine and the target process as Administrator | | Heap corruption / packed executable | Some regions are not pageable | Use “MEM_PRIVATE” filter in Memory Scan Options | | Virtual memory exhaustion | Too many scan results from previous scan | Clear scan results (New Scan) and use smaller start range |
If you are trying to do a scan for a value you don't know yet (like a health bar that has no numbers), you need to tell Cheat Engine to look for everything first.
100) or text.Before diving into the fixes, let’s break down what “Thread 0” actually means.