Instruction to setup add multiple documents/get multiple documents
To access certain web service features within ioXpress such as add multiple documents/get multiple documents, the security level for the client web browser and Microsoft .NET Framework must be configured to “trust” the ioXpress application.
Trust ioXpress application
1.1 Open internet explorer
1.2 select Internet Options under the Tools pull-down menu
1.3 Choose the Trusted Sites icon under the Security tab
1.4 Click the Sites button and enter www.ioxpress.com and click on the “Add” button, uncheck the option Require Server Verification (https:) for all sites in this zone and click OK.
Adjust .net security
go to www.ioxpress.com/ioxpress72, download the first two files on the default page, ioxcaspol32.bat and ioxcaspol64.bat. Run both files as an administrator.
Reboot your machine
If you still could not see the add multiple documents/get multiple documents components, I assume you have .Net 4.5 RTM installed on your machine. Please try below solution.
Managed .NET Control inside IE no longer works after installing .NET 4.5 RTM