1. On the NetCommunity server, browse to the %Program Files%\Blackbaud\NetCommunity directory.
  2. Right-click the ChartImages folder and select Properties.
  3. On the Security tab, ensure that the Network Service and/or ASP.NET Machine Account users have Full Control for this directory. If not, add these rights and click Apply.
  4. Click the Advanced button.
  5. Mark the Replace Permission Entries checkbox and click OK. Click Yes to the warning box.
  6. Click OK to exit the Properties box.
  7. Restart the IIS Admin service.

OR

Clear up free space on the hard disk of the NetCommunity Web Server