From V11.0.0 on it only supports 64bit, because Eclipse is 64bit only.
Extract from the release notes:
=========================
Version 11.0.0 (Jun 2019)
=========================
* Upgraded underlying Eclipse Framework to 4.10.0v201812 / CDT 9.6.0.
* Upgraded supplied GNU ARM Embedded Toolchain to GCC8 (2018q4-major)
* Windows version of product now only runs on Win64 (IDE v10.3.1 and
earlier ran on Win32 & Win64 platforms). Note that this change has
been driven by the fact that Eclipse framework is now 64-bit only.
[ Ubuntu and MacOS versions of product already only ran on 64-bit
platforms.]
