Here is how to deal with the error message “Low Memory” on the TI-Nspire:
This message pops up when there is no available memory to complete the task requested.
Important fact: A file listed as 1MB in the “My Documents” menu may require 12 MB or more to open.
Suggestions to fix memory errors (as suggested by TI here)
1) Delete some of the information in the document if possible.
2) Save the document by pressing [Ctrl]+[S] then close the document by pressing [Ctrl]+[W]. After the document is closed attempt to reopen the document.
3) Reboot the handheld by pressing the [Reset] button located on the back of the unit then then attempt to reopen the document.
4) Free up available memory on the handheld by pressing [Home] , to go to the My Documents menu, then delete documents you no longer need by pressing [del] then [Enter].
5) If the document contains images you can use an image editing software to scale the image to a size equal to or lower than the screen resolution which is 320×240. Doing this will reduce the document size.
6) If the document has a large amount of problems/pages you can attempt to break up the document into multiple smaller documents so they can be opened separately.