In the build release, I experienced “Cannot Find Module’.’ Error when building the app” In this release app folder.. I made an attempt to include a sliding menu that added a folder in ionic-angular module folder and added /umc to every code that imports navCtr for pushing pages.  I solved this problem by finding where the error was in Developer Console Chrome and navigating to the path to comment out the error. The error was coming from the index.ts.ds file in the newly added folder by the IDE. Once I commented out the code causing an error, I removed an extended /umc from all the imports from every page affected. After this step, I rebuild the app and it worked.