If you're seeing the "thread 0: Please fill something in" or "Stream read error" message, it usually means Cheat Engine is having trouble accessing its own temporary scan files or the game's memory. Try these fixes in order:
Run as Administrator: This is the most common fix. Right-click your Cheat Engine shortcut and select Run as Administrator to give it the necessary permissions to read game memory.
Check Disk Space: Cheat Engine creates large temporary "scanfiles" in your user folder during a search. Ensure you have at least 500MB to 1GB of free space on your primary hard drive. Clear Scan Settings: Go to Settings > Scan Settings.
Try toggling the MEM_MAPPED option. Some users find that unchecking this box resolves "Access Violation" or thread errors.
Alternatively, try setting a Custom Scan Location to a folder where you have full read/write permissions.
Disable Anti-Virus/Firewall: Some security software (like Comodo or Windows Defender) can block CE from accessing memory threads. Temporarily disable them or add Cheat Engine as an exception.
Verify Process Attachment: Ensure you have actually attached Cheat Engine to the correct game process by clicking the Computer Icon before starting your scan.
The "Scan error: thread 0: Please fill something in 100" typically occurs when a user attempts a scan without providing a valid input value in the scan field. Common Fixes for Scan Error Thread 0
Input a Value: Ensure the "Value" box in the main Cheat Engine window is not empty before clicking First Scan or Next Scan. If you're seeing the "thread 0: Please fill
Check Process Attachment: Verify that Cheat Engine is correctly attached to the target game process by clicking the PC icon and selecting the active executable. Scan Settings Adjustment:
Enable MEM_MAPPED: Go to Settings > Scan Settings and ensure MEM_MAPPED is checked.
Verify Scan Ranges: Ensure the "From" and "To" memory addresses are set to the default range (usually 00400000 to 7FFFFFFF).
Administrative Privileges: Always run Cheat Engine as an Administrator to ensure it has the necessary permissions to read the game's memory.
Security Software Conflict: Antivirus or firewall software (like Comodo) can block CE threads; try adding an exception or temporarily disabling the software. Troubleshooting Scan Failures (0 Results)
If your scan completes but returns 0 results, consider these alternatives:
Cheat Engine :: View topic - Scan error:thread 0:access violation?
Cheat Engine :: View topic - Scan error:thread 0:access violation? ... Scan error:thread 0:access violation? ... How do I cheat? . Cheat Engine Guide: Fixing "Scan Error Thread 0: Please Fill
The neon glow of Alex’s monitor was the only light in the room as the clock struck 3:00 AM. He was so close. The "Infinite Health" address was buried somewhere in the code of Abyssal Reach, a game notorious for its crushing difficulty.
He opened Cheat Engine, attached the process, and hit 'First Scan.'
Suddenly, the progress bar turned blood-red. A dialogue box popped up with a message he’d never seen: "Scan Error: Thread 0 please fill something in 100 new."
"What the hell?" Alex muttered, clicking 'OK.' The box didn't close. Instead, a new window flickered to life—a hex editor displaying memory strings that shouldn't exist. 00 00 HELP 00 0000 00 FILL 00 00
The "100 new" wasn't a memory limit; it was a countdown. In the reflection of his screen, Alex saw a shadow standing in the corner of his room. Every time the value in Thread 0 ticked down, the shadow moved closer.
He realized with a jolt of terror that the "something" the error wanted wasn't a value or a byte. It was a trade. He frantically typed 999999 into the value field, desperate to break the loop, but the error flashed again, faster this time. "Thread 0: 50 new. Please fill something in."
The air in the room turned ice-cold. The shadow was now at his shoulder, its hand reaching for the keyboard. Alex didn't look back. He realized the game wasn't scanning his RAM anymore—it was scanning him.
Type a valid value in the “Value” field before scanning. Never leave address range fields blank when manually
100 if you know the in-game number is 100.5000 for health, ammo, etc.If you’re doing an “Unknown initial value” scan:
Unknown initial value.Exact Value, type 0 or 1, then switch back.Check for corrupted settings (rare):
cheatengine.exe folder in %APPDATA%\Cheat Engine\ (backup your tables first).Reinstall Cheat Engine (latest version from official site) if the error persists across all games.
The most common reason for this error is that the "Value" input box (located next to the "Scan" button) is empty or contains only spaces.
100) or text into the Value box before clicking First Scan.The error often happens when your "Value" input does not match the "Scan Type" selected.
100).Highlight the value box and press Ctrl+A (Select All), then Delete. Type your value again manually—do not paste from an external source.
If you must paste, first paste into Notepad, then copy from Notepad into Cheat Engine.
Forum posts mentioning “cheat engine scan error thread 0 please fill something in 100 new” often refer to the “New Scan” button. After a user clears previous results or starts a fresh session, they click “New Scan” without entering a value.
The “100%” likely comes from a misunderstanding of progress bars—some users think the scan is 100% complete, but in reality, the error occurs at 0% because no value was given.
Remember: “New Scan” requires a value just like “First Scan.”