I'm a bit mystified actually.
So you've done Analysis >> Studies and selected "Moving Average Exponential", hit "Add" and it's appeared in the box marked "Studies to Graph". You've then hit "Settings" and set the EMA length to 100. In the top left of the Settings box is the colour to the right of "ExpMovAvg" a different colour from the chart background?
The fact that all 3 indicators are invisible suggest to me that somewhere the colour of the indicators is set globally to an invisble colour but I can't work out where, except in Chart>>Graphics Settings Global or the the Settings window for each study.
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