After I migrated from 4.1.1 to 4.2 version of Apex (on Oracle XE), all applications (about 10), on different workspaces , not work.
I followed instructions in installation manual (I installed apex a dozen times), and everything was ok - there is no error.
When run Application Builder, in tree view there is not shown any region except breadcrumb, but component view works ok and all regions and items appeared.
On Page 101, non of items (P101_USERNAME, P101_PASSWORD, ..) appeared in tree view - but on component view is ok.
When I run application, nothing happened - empty page.
I back up all application before upgrade.
After upgrade, application not show, but when i import same application, it works well.