CiviCRM Error - type E_ERROR was caused in line 550
This error is telling you that due to a filesystem (IO) error the system could not save a temporary file.

This could be due to:


Hardware issues with the storage medium.
No free disk space available.
Incorrect/insufficient permissions to save files in the location required.


You should check that the webserver/PHP user has permission to write to the location which will be in the full logs in your installation's ConfigAndLog folder in the CiviCRM files directory.