When you have a complex page with a Level 1 scroll area and lot of group boxes on a single page and try to move a field using arrow key, page becomes un responsive and CPU goes to 100% usage for one particular core. The control comes back after a minute. If you want to align lot of fields it becomes cumbersome. This is observed with PeopleTools 8.53.12 on a custom page with HRMS 9.1 on multiple windows 7 64 bit laptops (Dual Core with 8 GB RAM). Clearing the cache or rebooting the machine does not help.
Workaround : What we found is that changing the fields under a scroll area to a subpage (All fields must be level 0 in a subpage) and using that subpage resolves the issue. I have not seen this before in older PeopleTools releases (8.50 and earlier) and so it seems to me a new issue.
Oracle Support was able to replicate this issue and opened a new Bug 19492406 - APP DESIGNER GOES INTO NOT RESPONDING STATE WHEN MOVING A PAGE FIELD .
There is also a BUG 18773369 and 19565638 related to this issue.
This issue is fixed in 8.55 and 8.54.03. Currently there is no fix for 8.53, but the below workaround also works in addition to moving fields to sub pages. The fix may be included in 8.53.18.
Click on Application Designer Menu item Layout->Grid Settings..., set the Show Grid to No. This can minimize the refresh, but this is not a permanent setting. Every-time a page is opened, click Layout->Grid Settings..., set the Show Grid to No must be done.
If you are on lower 8.53 patch level you can request a POC fix which provides updates to psped.dll and pspnlrtwin.dll to resolve the issue.
Patch name : 19531601 and POC is POC-913314-02.