MSSIPOTF_E_TABLE_CHECKSUM (0x8009700C) Fix Guide

When This Error Hits

You'll see the MSSIPOTF_E_TABLE_CHECKSUM error — error code 0x8009700C — when Windows tries to validate a font file and finds the internal checksum doesn't match what the table header says it should be. This almost always happens during font installation, especially with OpenType (.otf) or PostScript Type 1 fonts. I've also seen it trigger when the Print Spooler tries to load a damaged font for rendering. A common scenario: someone copies a font from a thumb drive, double-clicks it to install, and gets this error halfway through.

Root Cause — Plain English

Every font file has a built-in checksum — think of it as a fingerprint. The file's table header stores the expected checksum value. When Windows reads the font, it recalculates the checksum from the actual data. If those two numbers don't match, Windows refuses to load the font. The culprit is almost always a corrupted font file. Maybe the download got interrupted, the USB transfer had a glitch, or the file was modified by some tool that didn't update the checksum. Sometimes the font was built incorrectly in the first place — happens with poorly exported fonts from design software.

The Fix — Step by Step

Don't bother with registry edits or system file checkers. The fix is straightforward. Let's kill this in four steps.

1. Remove the problematic font from the system.
   Open File Explorer and go to C:\Windows\Fonts. Find the font that caused the error. Right-click and delete it. If the font isn't there (sometimes the install fails before it lands), skip this step.
2. Flush the Print Spooler.
   Even if you're not printing, the spooler caches font data. Open Command Prompt as Administrator (right-click Start > Windows Terminal (Admin)). Run these commands:
   

   net stop spooler
   del /F /S /Q "%windir%\System32\spool\PRINTERS\*"
   net start spooler

   This wipes the spooler cache. If the spooler was holding a corrupted font reference, this clears it.
3. Re-download or re-copy the font file from its original source.
   Don't use the same copy that failed. Go back to the website or original package. If it's from a trusted source like Google Fonts, re-download. For a custom font, ask the designer for a fresh export. Transfer via a stable method — avoid USB drives that have been acting flaky.
4. Install the font using the right method for your Windows version.
   On Windows 10 and 11, right-click the .otf or .ttf file and select Install. Don't drag it into the Fonts folder manually — that skips Windows' validation and can cause issues down the line. If you get the error again, the font file itself is bad. Period. Don't try to fix it with a hex editor; that way lies madness.

Still Failing? Check These

If the error persists after re-downloading, here's the short list of what to check:

• User Permissions. Make sure your user account has write access to C:\Windows\Fonts. Rare, but I've seen domain policies lock this down. Run the installer as Administrator.
• Third-party font managers. Apps like FontBase or NexusFont sometimes hold file locks. Close them completely before installing.
• Windows update. KB5023778 (March 2023) and later updates tightened font validation. If you're on a weird build, run sfc /scannow from an admin prompt — but I've never seen that fix this specific error. Skip it unless you're desperate.
• Try the font on another machine. If it fails on a second computer, the file is toast. Bin it and get a fresh export.

That's it. 0x8009700C is stubborn but not mysterious. Bad file in, bad file out. Replace the font and move on.