Some things to check
(1) Is what you expect
(2) Is layer visibility off
(3) Is layer opacity set to zero
(4) Is the layer mode other than normal.
There are more that should be obvious but...
Text off the canvas, use View -> Show All
Text layer under a solid layer, move text layer up
black text on black background / white text on white background.....
Otherwise post a screenshot of what you have:
(1) Is what you expect
(2) Is layer visibility off
(3) Is layer opacity set to zero
(4) Is the layer mode other than normal.
There are more that should be obvious but...
Text off the canvas, use View -> Show All
Text layer under a solid layer, move text layer up
black text on black background / white text on white background.....
Otherwise post a screenshot of what you have: