RSTDSP is a parameter on the Create Display File (CRTDSPF) or Change Display File (CHGDSPF) command. It specifies whether data being shown at a display device by this display file is saved at the time the file is suspended (made temporarily inactive) so that a different display file can be used to show different data on the same device. If the data for this file is saved, it is restored to the display of the device when the file is used again. When *YES is specified for the Restore Display (RSTDSP) parameter, an image of the current display is saved when the display is suspended. When the display file is activated again, the saved image is used to restore the display to its appearance before being suspended.
According to Application Display Programming, the RSTDSP(*YES) parameter must be specified for the following keywords. If the parameter is not specified, data on the display can be lost if the file is suspended. You must ensure that the records that are on the display are the records that these keywords apply to. If the display file is suspended, the data must be restored to the screen so that the write operations to the record formats that use these keywords are valid.
WebFacing does not have the previous screen state for the display file to restore to if the display file has RSTDSP(*NO) specified. This would result in an IndexOutOfBoundsException in some cases. In other cases, the application may not be broken, however you may see displays different from 5250; for example, some windows overlap each other in WebFacing.
If you experience these problems, please make sure RSTDSP(*YES) is specified for the display files that are used in the application.