Three reasons why the error "The file could not be written to disk" appears in WordPress

One of the most frequent errors in WordPress appears when we try to upload an image in our publications and we did not succeed due to the error The file could not be burned to disk. This error can be shown for several reasons, and that is really a problem, since we have to analyze, one by one, all the possible causes until we find the one that really affects us.

Let's see the three most common reasons and their corresponding solution.

to) Directory permissions: If someone has modified the permissions in the directory where the images are uploaded (wp-content, uploads, or any other subdirectory), we will find ourselves with a permission problem that is very easy to solve. We just have to enter the server (it can be via FTP) and select the directory where the content is saved, indicating that the permissions must be 755, as shown in the image below:

b) Hard drive full: We have run out of disk space, so it is time to clean up or hire more space on the server. If the hard drive is really full, we will see that it is not the only error on our website, since nothing new can be generated, neither cache files, nor database increase (in case we have it in the same server). Another possibility is that the directory of temporary files has been filled (WordPress needs it to save material before publishing it in the corresponding directory), being necessary to delete the content from there or request those responsible for the support to carry out said action.

c) Security issues: It is possible that the file being uploaded has a security problem (it can be suspicious), and many servers block the upload to avoid major problems. The code shown below must be included in the .htaccess to deactivate the security lock, although it is important to verify it beforehand with the company that offers the hosting, since deactivating a security protection is not always a good idea.

Of course, there may be other reasons, but most of the time they are usually related to the three points mentioned above.