I encountered a similar issue while working in Visual Studio, where the problem stemmed from an incorrect url() path leading to the font file.

The error disappeared once I made the following change:

@@font-face{
    font-family: "Example Font";
    src: url("/Fonts/ExampleFont.eot?#iefix");

to this:

@@font-face{
    font-family: "Example Font";
    src: url("../fonts/ExampleFont.eot?#iefix");

For the solution, I needed to include type="text/css" in my link tag. The modification was made from:

<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,400,700" rel="stylesheet">

to:

<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,400,700" rel="stylesheet" type="text/css">

Following this adjustment, the issue was no longer present.

Ensure that your server is correctly serving the font files with the appropriate MIME type.

I encountered a similar issue while using nginx because some font MIME types were not included in its default /etc/nginx/mime.types file.

To resolve this problem, I added the missing MIME types to the specific location where they were needed, like so:

location /app/fonts/ {

  #Fonts directory
  alias /var/www/app/fonts/;

  #Include default types
  include mime.types;

  #Missing MIME types
  types  {font/truetype ttf;}
  types  {application/font-woff woff;}
  types  {application/font-woff2 woff2;}
}

If you need help extending the MIME types in nginx, you can refer to this guide: extending default nginx mime.types file

Dealing with a similar problem, I managed to resolve it by making the following adjustment

src: url("Roboto-Medium-webfont.eot?#fixit")

with this change

src: url("Roboto-Medium-webfont.eot?#fixit") format('embedded-opentype')

Encountered an issue across various browsers except for Chrome. A crucial point to note is the comma between URL and format - this simple adjustment resolved the problem across all browsers. Interestingly, removing the "format" section also worked fine, but I opted to keep it anyway.

@font-face {
  font-family: "Roboto";
  src: url("~path_to_font/roboto.ttf"), format("truetype");
}

Occasionally, this issue arises when you transfer fonts using the incorrect FTP method. Fonts should be transferred via FTP in binary format, not ASCII. (It might seem counterintuitive depending on your perspective, haha). If you upload font files with the ASCII method, you may encounter this error message. If you use the 'auto' method to transfer your files and still receive this error message, attempting to force the binary method during FTP could resolve the issue.

By changing the code from format('woff') to format('font-woff'), the issue is resolved.

Only a small adjustment compared to the solution provided by Germano Plebani

 @font-face {
  font-family: 'MyWebFont';
  src: url('webfont.eot'); /* IE9 Compat Modes */
  src: url('webfont.eot?#iefix') format('embedded-opentype'), /* IE6-IE8 */
       url('webfont.woff2') format('woff2'), /* Super Modern Browsers */
       url('webfont.woff') format('font-woff'), /* Pretty Modern Browsers */
       url('webfont.ttf')  format('truetype'), /* Safari, Android, iOS */
       url('webfont.svg#svgFontName') format('svg'); /* Legacy iOS */
}

Make sure to check if your browser can properly render this source and identify its type

My experience with this issue occurred when I was trying to use a Google font with https. After switching to http, the error disappeared. (I made sure to confirm multiple times that this was indeed the cause)

This is what I modified:

@import url(https://fonts.googleapis.com/css?family=Roboto:300,400,100,500,900);

To:

@import url(http://fonts.googleapis.com/css?family=Roboto:300,400,100,500,900);

I encountered a similar issue with font awesome version 4.4 and was able to resolve it by eliminating the woff2 format from my code. The problem only occurred in Google Chrome.

@font-face {
  font-family: 'FontAwesome';
  src: url('../fonts/fontawesome-webfont.eot?v=4.4.0');
  src: url('../fonts/fontawesome-webfont.eot?#iefix&v=4.4.0') format('embedded-opentype'), url('../fonts/fontawesome-webfont.woff?v=4.4.0') format('woff'), url('../fonts/fontawesome-webfont.ttf?v=4.4.0') format('truetype'), url('../fonts/fontawesome-webfont.svg?v=4.4.0#fontawesomeregular') format('svg');
  font-weight: normal;
  font-style: normal;
}

The issue I experienced was due to an inaccurate file path specified in my .htaccess file. Make sure to verify the accuracy of your file paths.

One oversight I made was neglecting to switch FTP into binary mode prior to transferring the font files.

Revision

To check for this, try uploading different types of binary data such as images. If they also don't show up properly, this could be the root of the problem.

Encountered a specific Issue with downloading fonts in AWS Amplify. The problem was solved by including the woff2 format in the default Target address /index.html rule within the App settings / Rewrites and redirects. This adjustment successfully resolved any errors related to woff2 fonts. 👍

Before

</^[^.]+$|\.(?!(css|gif|ico|jpg|js|png|txt|svg|woff|ttf|map|json)$)([^.]+$)/>

After

</^[^.]+$|\.(?!(css|gif|ico|jpg|js|png|txt|svg|woff|woff2|ttf|map|json)$)([^.]+$)/>

After encountering a similar issue, I was able to resolve it by including 'Content-Type' : 'application/x-font-ttf' in the response header for all .ttf files.

In my situation, I encountered an issue where creating a SVN patch file that included adding font files caused problems. Here's what happened:

1. Added font files from my local file system to the subversioned trunk
2. Trunk functioned normally
3. Created a SVN patch of the changes in the trunk, including the addition of font files
4. Applied the patch to another branch
5. Font files were added to the subversioned branch (and could be committed), but they were corrupted, leading to errors.

To resolve this issue, I had to manually upload the font files into the branch from my local file system. It seems that the problem arose because SVN patch files may convert everything to ASCII format and might not retain binary data for font files. However, this is just speculation on my part.

When working with React and Gatsby in my own experience, I encountered a similar issue that was resolved by carefully verifying all of the file paths. In my setup using Sass, the Gatsby source files were searching for fonts in a location that differed from where the compiled files were located. By duplicating the font files into both locations, this discrepancy was rectified and the problem disappeared.

While trying to download a template, I encountered a problem where the font files turned out to be empty. It seemed like there was an issue with the download process, as Chrome displayed a generic error message. Initially, I tried changing from woff to font-woff thinking it would fix the issue, but instead, Chrome simply ignored the fonts altogether. Ultimately, I had to manually locate and replace each font file in order to resolve the problem.

My issue was similar, however my problem stemmed from a corrupted font that was impossible to decode. The culprit turned out to be a configuration within Maven. By adding specific font extensions to the maven-resources-plugin's nonFilteredFileExtensions, I was able to resolve the issue:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-resources-plugin</artifactId>
    <configuration>
        <nonFilteredFileExtensions>
            <nonFilteredFileExtension>ttf</nonFilteredFileExtension>
            <nonFilteredFileExtension>otf</nonFilteredFileExtension>
            <nonFilteredFileExtension>woff</nonFilteredFileExtension>
            <nonFilteredFileExtension>woff2</nonFilteredFileExtension>
            <nonFilteredFileExtension>eot</nonFilteredFileExtension>
        </nonFilteredFileExtensions>
    </configuration>
</plugin>

To ensure static content is served when using express, include the following code snippet: const server = express(); server.use(express.static('./public')); // Specify 'public' as the root folder of your app, which may contain fonts at different levels like public/fonts or public/dist/fonts... // If you are utilizing connect instead, refer to a comparable setup.

My technology stack includes .Net Framework 4.5 running on IIS 7.

To solve the issue, I placed the Web.config file in the same folder as the font file.

The following is the content of my Web.config file:

<?xml version="1.0"?>
<configuration>
  <system.web>
    <authorization>
      <allow users="*" />
    </authorization>
  </system.web>
</configuration>

In scenarios where the server is involved (as opposed to being on localhost), it might be worth attempting a manual font upload, as certain FTP clients like FileZilla have been known to corrupt files leading to potential issues. Personally, I opted to manually upload via the Cpanel interface.

Google encounters setbacks too...

Just yesterday, an issue cropped up due to a glitch on Google's end, affecting Win7 and some Win10 users.

https://github.com/google/material-design-icons/issues/1220

Luckily, the problem was swiftly resolved within a day.

I highly recommend always keeping backups of essential files sourced from CDNs like these fonts.