If you receive an error message about not enough space, you may need to try re-installing ESO.
At least 80 GB of hard drive space is required to install The Elder Scrolls Online on PCs, and at least 85 GBs is required on Macs. Patches can be anywhere between 50 megabytes to 25 GBs in size. You will also need enough room for the patch to apply.
After freeing up some space from your hard drive, you should reinstall and see if you still get this error or not.