The OP states it is an etrex 30x in the title

But many things could cause this....
Are you sure you actually sent a map of the area you're trying to view?
How big is the map you dowloaded? How big is the map file on the GPS?
You said "maps" (plural). Does that mean you sent multiple maps to the device at the same time? If so, looking on the GPS (and on the memory card if you have one), what are all the files that have a .img extension?
To troubleshoot, remove all maps you have installed then install just one map and see if that works. If so, add another map and so forth until you have a problem.
Garmin devices have limits on maps that are unrelated to their size im megabytes. If you load a bunch of maps at the same time, you can easily hit this limit. Again, remove everything and try loading just one map (or a portion of one map).
But before doing ANYTHING, make a full backup of all the files in internal memory. Just make a folder on your computer and drag or paste all the files there. This is cheap insurance against a future disaster.
