Installed Oracle ODP.net client and after that, Toad now gets the error below when connecting to an Oracle database:
"Access violation at address 0F85DEEE in module 'oran11.dll'. Read of address 4F85E1B0."
Other Oracle tools/programs (not just Toad for Oracle) also started getting this error.
Re-install the Standard Oracle Client and ensure it is installed as last or installed after the Oracle ODP.net client.