I’ve received an “Invalid JSON string” error. What do I do? [Moodle version 3.2]
An invalid JSON error can occur for many reasons.
- The most common issue is usually associated with a file upload attempt, and can occur when:
- Attempting to upload a file with the same name as another already-uploaded file;
- Attempting to upload a file that is too large for the system (Sitewide the limit is 64MB; however, individual classes may vary—you can check your course settings);
- Attempting to upload a file type that the system doesn’t recognize; or
- Attempting to upload a file with a period or special characters in the file name.
- Another common cause of this issue is the age of the system or version of the browser that is being used. The older systems/browser versions are not as compatible as our software is continually upgraded to provide the best security. We recommend keeping your browser and operating system current with all updates.
Note: if you have an older system and are considering an upgrade, Technology Services has put together both a laptop purchasing portal and a list of the recommended system requirements to be able to fully use all that Trinity has to offer.
On campus, the default browser is currently Internet Explorer. If you are using a different browser, let me know and I can provide steps for that browser!
Note: you can click on any image to view a larger version of the image.
- Open Internet Explorer. If it is already open, log out of Moodle.
- In the upper right corner, locate the set of three icons: a house (IE Homepage), a star (IE Favorites), and a gear (IE tools).
- Click on the “gear” to bring up IE’s tools:
- From the list of Tools, choose the “Internet Options” link near the bottom:
- The “Internet Options” will open in a pop-up window. You will be located in the “General” tab of the “Internet Options” window. Look to the middle of the “General” screen and find the area labeled “Browsing History.” Click on the “Delete” button in that area.
- On the next screen you have two options.
- OPTION #1 – Leave the default boxes “as is” (leave checked boxes checked and unchecked boxes unchecked). Click the “Delete” button at the bottom of the screen. THIS WILL DELETE ANY SAVED PASSWORDS — use option #2 to save your passwords.
- OPTION #2 – If you have saved Moodle as one of your browser’s favorites, you will want to uncheck the first box so that IE clears any Moodle-related files and cookies as well. Once the box next to “Preserve Favorites website data” is unchecked, scroll down to the bottom and click the “Delete” button.
- Either option will bring you back to the “General” tab in the “Internet Options” pop-up box while IE thinks through the deleting process. Depending on the number of files and cookies you may have, this could take upwards of a couple of minutes. You will know the browser is done, because you will receive a notification at the bottom of the screen. When it shows up, you can click the “OK” button to return to your browser.
- Now you can log back into to Moodle and try uploading again.