Firefox 68 introduced a new security measure to prevent untrusted local files from reading files in the same folder or subfolders. Unfortunately this also prevents StatPlanet Cloud from running on your local drive / offline.
The new security measure can be disabled as follows:
- In Firefox, open up a new tab. Type or paste about:config in the address bar and press Enter.
- A button appears asking if you accept the risk to change advanced settings. Click that you accept the risk.
- Type unique in the search box, which will filter the list for words containing this word.
- Double-click the privacy.file_unique_origin preference to switch the value from true to false
Please note: There is a reason why Firefox 68 introduced this new security measure. It is important to avoid saving any pages or files from untrusted websites. If you are not sure that a site can be trusted, then make sure to save the files or pages in a new folder such as a sub-folder 'untrusted' in your downloads folder. This will prevent the file from accessing any valuable content within the folder it is saved.