ODAC OLE DB provider "OraOLEDB.Oracle" for linked server supplied inconsistent metadata for a column I am using SQL Server 2014 linked server to connect to an Oracle 11gR2 (11.2.0.3) database, using the ODAC 12.1.0.2.4 Oracle OLE DB Provider. I have a stored procedure that lives in a SQL 2014 database and inserts data from a local table into a remote Oracle table via the linked server, using the following syntax: 

insert into LinkedServerName..RemoteSchema.RemoteTable(column) 
select column from localSQLServerTable


However, I receive the error below on the line of the insert: 


  Msg 7356, Level 16, State 1, Procedure {MyProcName}, Line 1 The OLE
  DB provider "OraOLEDB.Oracle" for linked server "{MyLinkedServer}"
  supplied inconsistent metadata for a column. The column "{columnName}"
  (compile-time ordinal 23) of object "{remote table name}" was reported
  to have a "DBCOLUMNFLAGS_ISFIXEDLENGTH" of 16 at compile time and 0 at
  run time.


The column in question is defined in Oracle as CHAR(1 BYTE) data type.

Installed "64-bit ODAC 12c Release 4 (12.1.0.2.4) Xcopy for Windows x64", download name "ODAC121024Xcopy_x64.zip" from http://www.oracle.com/technetwork/database/windows/downloads/index-090165.html
Even though Oracle support note 207303.1 states that the 12c client works with 11gR2 client, this error seems to be caused by a compatibility issue between the 2 different versions.  To fix, I followed these steps: 


Uninstall the 12c ODAC version, by opening an Admin command prompt, changing directories to the installed Oracle home folder, and running: uninstall.bat all d:\oracle, where d:\oracle is my Oracle home location.
Remove the PATH environment variables
Reboot 
Install the 11.2.0.4 ODAC version "64-bit ODAC 11.2 Release 6 (11.2.0.4.0) Xcopy for Windows x64", download the "ODAC112040Xcopy_64bit.zip" option.  Make sure you install via Admin command prompt (the install command is: install.bat all d:\oracle11gr2 odac11gr2).  Download from: http://www.oracle.com/technetwork/database/windows/downloads/index-090165.html 
Add back the PATH environment variables for d:\oracle11gr2;d:\oracle11gr2\bin
Reboot again