Your PC is blocking Cheat Engine from accessing the game's memory threads. 100% Best Ways to Fix the Scan Error 1. The "Select Process" Check (Most Common Fix)
The most literal interpretation of the error is the most common fix.
: Uncheck the "Fast Scan" alignment check box to force a deep, sequential byte check.
Use Lua to read memory if standard scan fails. Phase 8: Dealing with Complex Memory Scan with Memory Alignment : Toggle alignment settings. Disable Fast Scan in Settings -> Scanner . Use Ignore for specific memory regions. Check for VirtualProtect calls. Use Debugger -> Break and Trace . Check Settings -> Scan Settings for Memory Protection . Use CE to Suspend target process before scanning. Try a Different Pointer. Scan for String or Unicode . Disable Auto-Attach . Phase 9: Final Troubleshooting & Reinstalls
Ensure you select the right Cheat Engine version. 64-bit Games: Always use 64-bit Cheat Engine . WebGL/Browser Games: Need MEM_MAPPED enabled. Emulators: Use ZSNES or RetroArch native cheats instead. Games with 0 for true (1 for false). Games with 0 for false (1 for true). Scenarios where value only exists when open. Values that only change when taking damage. Values that only change when buying an item. Scenarios involving Double precision. Scenarios involving Float precision. Check MEM_PRIVATE again. Re-evaluating the Problem (86-100) Is it the correct process? (Look for the main .exe ). Did you select the correct scan region? Is the address pointer-based? Are you sure the value is not encrypted? Try 8-byte again. Try 4-byte again. Try All again. Try Unknown again. Check if the game is using VirtualQuery . Reset Memory Map . Re-attach Process . Restart Computer . Disable Cheat Engine settings. Try a different game to test. Search forum.cheatengine.org for that specific game. 🔒 Handling Encrypted or Hidden Values Your PC is blocking Cheat Engine from accessing
If you are trying to hack your favorite offline game and hit the dreaded message, you aren't alone. This is one of the most common hiccups for both beginners and veteran users of Cheat Engine.
Games with basic anti-cheat or Windows User Account Control (UAC) can block Cheat Engine from spawning scanning threads. Close Cheat Engine entirely. Right-click the on your desktop. Select Run as administrator . Open your game and attempt the scan again. Advanced Troubleshooting
If you are unsure whether a game calculates health using integers (4 Bytes) or decimals (Float), select All under Value Type. This prevents the scanner from passing illegal parameters to Thread 0.
refers to the primary worker thread tasked with starting the memory scan. : Uncheck the "Fast Scan" alignment check box
Sometimes, changing scan types mid-search without resetting the current session confuses the memory allocation threads. Step-by-Step Fixes for Thread 0 Errors
Avoid direct memory scanning if it keeps crashing.
Set to Float or Double if your number contains decimals.
Specifically for Unity/Unreal Engine games. Disable Fast Scan in Settings -> Scanner
If an anti-cheat system is blocking Thread 0, you must change how Cheat Engine interacts with your CPU. Navigate to > Settings > Extra .
Change it to calc.exe or notepad.exe to confuse process-checking anti-cheats.
If the value is 10.5 , scan for 1050 (value × 100) 1.2.5.
Follow these troubleshooting steps in order to resolve the issue and get your scans working again. 1. Input a Valid Value