It is not clear on your post which version of Illustrator you are using.
Please accept my sincere apology for the inconvenience. Please get in touch with us at any of the other support channels – https://helpx.adobe.com/support.html . Since this is not a generic issue that we can reproduce at our end, we will need someone to look into your machine to figure out what is going on here.
Please do take a moment to review our support policy for removable and network media if you are using it: https://helpx.adobe.com/illustrator/kb/illustrator-support-networks-removable-media.html