It may or may not be a problem - if you don’t get a lot of this messages for a longer period of time, then you don’t need to worry. But if you do then it is a problem.
Please have a look here for a possible solutions - Memory Alerts
You need to make sure you’re running on the latest stable firmware for the device, and that you have disabled all background services. From memory they come with things like AirPin and e@home media centre installed. Both need to be removed to free resources. Then install the latest Xibo for Android Player and it should be better.
Please note also if you’ve paid for a licence for Xibo for Android then you’re entitled to use the Spring Signage service desk for Android support. That’s manned weekdays 8am to 4:30pm UK time and that’s the best place to get help. We try and keep on top of Android support here but as a paying customer you should get better service there.