I’m not sure, but I am guessing that there are some mismatched shared files between Keyman and Keyman Developer – this is one of the perils of installing alpha software, in that we have not yet necessarily covered all the bases for install and upgrade/downgrade.
To resolve this, I would uninstall both Keyman and Keyman Developer, and restart your computer. Then check the following folders for files that may be left over, and remove them:
%programfiles(x86)%\Keyman (On English language systems,
C:\Program Files (x86)\Keyman)
%commonprogramfiles(x86)%\Keyman (On English language systems,
C:\Program Files (x86)\Common Files\Keyman)
Normally, you would not need to cleanup the registry, but you can check and remove:
Then you should be able to install Keyman 14 and Keyman Developer 14 without problems!
Note that mixing Keyman and Keyman Developer versions is not currently supported – i.e. you should run version 14 of both. With version 15 onwards, Keyman Developer will be completely independent of Keyman, and you will be able to run mismatching versions in the future.