Shouldn't be required as it happens with every new, old, and so on capx file.
Steps to reproduce:
I can't, just happens all the time
In the first screenshot you will noticed at the bottom how it says Cancel, Help, Back, and Next. This is normal. However in the second screenshot you will notice how I can click nothing but the "object". In order to do anything I need to press Tab and then assume I a on the Okay button, then press enter.
I should be able to see the back button and change the function, and click the cancel or okay button to continue.
Operating system & service pack:
Windows 7 Ultimate 64-bit SP1
Construct 2 version:
118, However happened from about 2 weeks after Construct 2 Release.
EDIT: FIXED! Following the 1st reply in this post:
I fixed the issue by going into preferences and clicking Reset Dialog, and then restarting the program.
Renaming the post and hoping it will help others.