Getting "This build of IntelliJ IDEA has expired" when running "buildSearchableOptions"

Probably, you are using EAP build as target IDE version which is limited by 30 days, and then indeed expires. You should use a release version, e.g. 2019.1.3.

Also, make sure your build script points to the latest release version - see https://intellij-support.jetbrains.com/hc/en-us/community/posts/360003760139-Problem-developing-a-plugin-for-idea-ultimate-and-webstorm-build-expired

Thank you, 

I was using

IU-191.6707.61

I updated it to

IU-191.7479.19

and now it builds correctly

Cheers