File Diagnostic Center
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Common File Problems
58 step-by-step guides — find your issue and fix it with the right tool.
Archives
View category →ZIP File Password Forgotten or Lost
You created a password-protected ZIP but forgot the password, or received an encrypted ZIP without the password.
ZIP Split Archive — Missing Parts (z01, z02)
A multi-part ZIP archive (.zip + .z01, .z02...) will not open because one or more parts are missing or incomplete.
ZIP File Shows CRC Error When Extracting
Extraction fails with "CRC failed" or "CRC does not match" — one or more files inside the ZIP are corrupted.
ZIP File Extraction Is Extremely Slow
Extracting a ZIP file takes far longer than expected — hours instead of minutes, or progress appears to stall.
ZIP File Cannot Be Opened — Invalid Archive Error
Attempting to extract a ZIP file produces "Not a valid archive", "Cannot open file", or "The compressed file is damaged or incomplete".
Audio
View category →OGG File Not Recognized or Playing on Windows
OGG audio files show as unknown file type or fail to play in Windows Media Player on Windows 10 or 11.
WAV File Has No Sound or Audio is Silent
A WAV audio file plays silently — no audio is heard even though the file size and duration appear normal.
FLAC File Not Playing on iPhone or Android
FLAC audio files do not play on iPhone or Android — the default music apps show an error or do not recognise the format.
MP3 File Has Static, Crackling, or Distorted Audio
An MP3 file plays with unwanted noise — static, crackling, buzzing, or distorted audio that was not in the original recording.
Images
View category →Image Colors Look Different When Printed vs. On Screen
Your photo or design looks correct on screen but prints with different, washed-out, or shifted colors.
PNG Shows White Background Instead of Transparent
A PNG file that should have a transparent background is showing white or a colored background when opened or used on a website.
Image Looks Pixelated or Blurry After Resizing
Your image becomes blurry, pixelated, or jaggy after you make it larger or change its dimensions.
Screenshots Look Blurry on Retina / HiDPI Displays
Screenshots you take appear blurry or low-resolution when viewed on a Retina Mac, 4K monitor, or HiDPI display.
Image Appears Different Colors on Different Screens
An image looks correct on one monitor but appears too warm, too cool, washed out, or oversaturated on another screen or device.
HEIC Photos Not Opening on Windows 10 or 11
iPhone HEIC photos show as unsupported or unknown file type on Windows 10 or Windows 11.
PNG File Is Too Large for a Website
Your PNG image is slowing down your website because it is too large — PNG files for photographs are often 5–20× larger than they need to be.
Image Resolution Too Low for Printing
Your image looks fine on screen but prints blurry, pixelated, or low quality — the resolution is not high enough for print.
JPG Image Loses Quality Every Time It Is Saved
Re-saving a JPG repeatedly causes the image to degrade with each save — visible as increasing blurriness and compression artefacts.
GIF File Not Animating — Shows as a Static Image
An animated GIF displays as a single still frame instead of playing the animation.
WebP Image Not Showing in Email
A WebP image attached to or embedded in an email appears broken, as a download link, or does not display at all in the recipient's email client.
Image File Is Too Large to Email
Your image file exceeds the attachment size limit for Gmail, Outlook, or another email client.
Image Has Wrong Colors After Converting
Colors look washed out, shifted, or completely different after converting an image from one format to another.
File Is Too Large to Send on WhatsApp
WhatsApp limits file attachments to 100 MB for documents and 16 MB for images. Your file exceeds the limit and cannot be sent.
Transparent Background Becomes White After Conversion
When converting an image with a transparent background (PNG) to JPG, the transparency is replaced by a white or coloured background.
Image Looks Blurry or Pixelated After Upload
Your image appears blurry, soft, or lower resolution after uploading to a website, social media, or app.
Office Documents
View category →Excel File Shows #VALUE!, #REF!, or #NAME? Errors
Cells in your Excel or XLSX spreadsheet show error codes like #VALUE!, #REF!, #NAME?, or #N/A instead of calculated results.
Word Document Shows Track Changes or Review Markup
Your Word document is showing all the edits, deletions, and comments from Track Changes and you need to accept or hide them.
CSV File Shows Garbled Characters in Excel (Encoding Fix)
CSV file displays ?? or garbled characters instead of accented letters, Asian characters, or special symbols when opened in Excel.
Word Document Shows Wrong Fonts or Garbled Text
A DOCX file opens with fonts substituted, text garbled, or characters showing as squares and question marks.
Excel File Is Corrupted and Cannot Be Opened
Excel shows "the file is corrupt and cannot be opened" or "we found a problem with some content in filename.xlsx".
Word Document Is Corrupted and Cannot Be Opened
Microsoft Word shows "the file cannot be opened because there are problems with the contents" or "Word experienced an error trying to open the file".
PDF Page Numbers Are Wrong After Merging
After merging multiple PDFs, the page numbers in the document don't match the actual pages — they restart at 1 or show the original numbering from individual files.
PDF Always Opens on the Wrong Page
Every time you open a PDF it jumps to a specific page instead of the beginning, because an initial view page number is embedded in the file.
PDF Text Cannot Be Selected or Copied
You can't highlight, select, or copy text from a PDF — it behaves like an image even though it looks like text.
PDF Shows Wrong Characters or Squares Instead of Text
Text in your PDF appears as squares, question marks, or completely different characters because the fonts are missing or not embedded.
PDF Has Blank Pages When Converted From Word
When you export a Word document to PDF, some or all pages appear blank in the resulting PDF.
Scanned PDF Is Too Large — How to Reduce Scanned PDF Size
A PDF created by scanning physical documents is extremely large — often 5–50 MB per page — and needs to be reduced for emailing or uploading.
PDF Cannot Be Edited — Content Is Locked
When you try to edit a PDF, all editing tools are greyed out or disabled — the document has editing restrictions applied.
PDF Is Password Protected — Cannot Open
A PDF requires a password you do not have, cannot remember, or were never given.
How to Combine Multiple Images Into One PDF
You have several image files (JPG, PNG, or a mix) that need to be combined into a single PDF document.
PDF Text Is Not Selectable or Searchable
You cannot highlight, copy, or search text in the PDF — every page is an image rather than real text.
PDF Won't Print Correctly
The PDF prints blank pages, missing content, garbled text, wrong orientation, or cuts off the edges.
PDF Pages Are in the Wrong Order
Your PDF pages are scrambled, reversed, or out of sequence after merging, scanning, or exporting.
PDF File Too Large to Upload or Email
Your PDF exceeds the file size limit for an email attachment, government form, or online portal.
PDF File Corrupted or Damaged
Your PDF opens with errors, shows garbled content, or refuses to open entirely.
Presentations
View category →PPTX vs PPT: Which PowerPoint Format to Use
Understand the difference between PPTX and PPT formats and when to use each for maximum compatibility.
Presentation Animations Not Playing
Fix PowerPoint animations that do not play, are skipped, or appear static when presenting.
Presentation Fonts Missing After Sharing
Fix font substitution issues when PowerPoint or Keynote presentations display wrong fonts on another computer.
PowerPoint File Not Opening
Fix PPTX and PPT files that refuse to open in PowerPoint, Google Slides, or LibreOffice Impress.
Video
View category →Video Cannot Play — Codec Not Supported or Missing
Your video player shows an error like "codec not found", "format not supported", or plays with no video/audio because the required codec is missing.
Video Plays But Has No Sound
Your video file plays back visually but there is no audio — either the audio track is missing, the codec is unsupported, or the volume is muted.
Video File Too Large to Send by Email or Upload
Your video file is too large to attach to an email, upload to a form, or share on social media — you need to reduce its file size.
MKV File Not Playing on Windows — Codec Error Fix
MKV video files produce codec errors, play with no video, or do not open in Windows Media Player.
MOV File Not Playing on Windows — Fix QuickTime Error
MOV video files from iPhone or Mac show an error or play without video on Windows Media Player.
Audio Is Out of Sync With Video
The audio in a video file plays ahead of or behind the video — lips do not match what is being said.
Video Thumbnail Shows Wrong Frame
The video file's preview thumbnail shows the wrong frame — a black frame, the last frame, or an unrelated still.
Video File Is Too Large to Share or Upload
Your video file exceeds the upload limit for WhatsApp (16 MB), email (25 MB), or a web platform.
Video Has Picture But No Sound
A video file plays visually but there is no audio — the video track is fine but the audio track is silent or missing.