This symptom only applies to the application running on the XPR and XPR2, remote users are usually not effected unless memory drops low enough. The Xpress server is still running serving remote logins in most of the cases seen, only the local user interface is effected. Since it is a browser memory leak, it is possible that other symptoms may occur such as problems logging on remotely, screen data stops updating etc... It just depends on a unique combinations of factors what symptoms you may see.
This type of error is due to a WinCE5 Browser memory leak issue engineering identified where random applications of any size will eventually need rebooted if left run long enough. The XPR and XPR2 only run the WinCE5 OS and can not be upgraded to a later version Since it is in the CE5 Browser, it was necessary to make a work around until we could release a version of the hardware that supports an updated WinCE version. Units that do not run 24/7 usually do not see the problem since it is rebooted at a frequency greater than the frequency of the error.
A new tag was created in Xpress 3.1 to reset the local browser instance on the XPR so you don't have to power cycle. I am attaching an example application and documentation showing how it works. Other than rebooting the XPR/XPR2 at a higher frequency than the error occurs, this tag that closes and reopens the browser is the way to prevent the low memory condition.
Download and unzip the linked Xpress Project then copy the extracted file with extension of .lrp into your Xpress Projects Folder. The other files can be stored anywhere.
NOTE: The current release of hardware for Xpress that is wide screen and models start with XT have WinCE 7 and we no longer see the browser leak. If you have any of them on machines, the attached files do not apply.