Hi there!

Sorry for your experience.

Which template are you using there? And what are your system specifications?

Would you please try to change the featured image in the 'Bog Media' tab? Same issue happens?

Best Regards

Hi,

1. Tab "Images & Links" is from Joomla Core. Not managed/overriden from our template.
2. Use different .jpg file, with neutral name (demo.jpg) and try use it again.
3. Your problem can be caused by Server security settings or by extra installed plugin.
4. Are you able to upload images using Joomla Media Manager (Content > Media) ? Check that!.

Extra Tip!

To be sure, change template to Casiopea, make it default for 90sec, and check Tab "Images & Links" again.