When you run the new version there are two screen sizing options. One is called Fixed, the other is called Responsive.

On the right side of your Designer screen, in the far right under Properties, you should see a display like the one above.
If you check Fixed as shown above, your app should run pretty much as it did before. The compiler is supposed to default to Fixed when an app created with versions 144 and lower are run in AI2 version 145 (MIT's latest release). That did not happen? Did you change manually from Fixed to Responsive? If you switched to Responsive, you will have to do a lot of layout changes. If you want things the way they were, you should NOT use responsive mode unless you are prepared to make, perhaps, significant changes in your app. Having Responsive work requires user input to make it work.
Is the problem you have in a multi screen app or in a single screen app?
If you made no changes to the Sizing, please tell us on which version of Android you use and your phone model.
Are you using Leadbolt?
MIT did a lot of testing before release and 'older' projects compiled and the screen rendered very much like on the versions prior to 145. Could you please provide screenshots of your app screen before the change and current. This should help MIT understand the problem.
Regards,
Steve