Unlike many utilities, mscreen's complex responsibilities require a number of conditions for correct functionality. By following the suggestions here, you should be able to avoid some of the more common mistakes made by new mscreen users.
In preparing to use mscreen, make sure your terminal works with the program. Find out how much screen memory is provided by consulting your terminal manual. The mscreen utility uses the file /etc/mscreencap to determine how to change screen images for your particular terminal. As shipped, /etc/mscreencap is supplied with only a few terminals. To use mscreen with other terminals, configure the /etc/mscreencap file before using your terminal. If you run mscreen on a terminal that does not have an entry in /etc/mscreencap, mscreen fails.
If you are sure your terminal works with mscreen and you have a working mscreencap, but mscreen still fails:
You may need to create more pseudo-ttys if the pseudo-ttys currently on your system are in use.
Make sure the /etc/mscreencap for your terminal is correct. Use one of the examples in /etc/mscreencap to check the way your function key output sequence is mapped to a particular mscreen command. You must log in separately to each screen you intend to use.
If you are testing an mscreencap entry and you have trouble with the screens, you should do the following: