I was trying to install only x64 version OTT on Windows 11 x64. After "Choose Components" page, the setup recommended me to choose installation folder location for the x86 version, instead of the x64 version. I cliked "Next" and the .dll file got installed in D disk drive. Can you please fix this?
Try re-running the OTT_x64.dll installer again and select the VST2 folder location set in your DAW and not the x86 folder.
Open a support ticket with [email protected] if you are still stuck. Include your OS/DAW version and full screen shots of the folder location you are installing to and the VST2 folder location set in your DAW.