Hi big
Could you please let us know which Leconfe version you are currently using?
Then, you can try the following steps to resolve the issue:
1. In the Administrator menu, run the “Fix broken public storage/plugins” tool.

2. Based on a similar case discussed here: Image failed to upload, the issue usually occurs because the symlink function has been disabled on the server side. Please make sure the symlink function is enabled and working correctly on your server.
If the issue persists, please check the error_log generated when saving the image. You can find the log file in the following folder: storage/logs
Kindly share your findings so we can assist you further.