A possible solution can be the following:
1. Find the machine.config file and make a backup of it in case needed. An example of how the path to the file can look:
- C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\Machine.Config
2. The block to pay attention to is <DbProviderFactories>, an example of how it can look is below:
<system.data>
<DbProviderFactories>
<add name="IBM DB2 for i5/OS .NET Provider" invariant="IBM.Data.DB2.iSeries" description=".NET Framework Data Provider for i5/OS" type="IBM.Data.DB2.iSeries.iDB2Factory, IBM.Data.DB2.iSeries, Version=12.0.0.0, Culture=neutral, PublicKeyToken=9cdb2ebfb1f93a26"/>
<add name="Microsoft SQL Server Compact Data Provider" invariant="System.Data.SqlServerCe.3.5" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=3.5.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"/>
</DbProviderFactories>
<DbProviderFactories/>
</system.data>
3. In the machine.config file under the Vx.xx folder, look for lines like (note that there are two separate DbProviderFactories nodes, one with data and one empty node):
<system.data>
...
<DbProviderFactories />
</system.data>
4. Delete this line only (the empty DbProviderFactories node):
<DbProviderFactories />
5. Close and save the file. For example, the above example block when modified correctly would look like the following:
<system.data>
<DbProviderFactories>
<add name="IBM DB2 for i5/OS .NET Provider" invariant="IBM.Data.DB2.iSeries" description=".NET Framework Data Provider for i5/OS" type="IBM.Data.DB2.iSeries.iDB2Factory, IBM.Data.DB2.iSeries, Version=12.0.0.0, Culture=neutral, PublicKeyToken=9cdb2ebfb1f93a26"/>
<add name="Microsoft SQL Server Compact Data Provider" invariant="System.Data.SqlServerCe.3.5" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=3.5.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"/>
</DbProviderFactories>
</system.data>