If I use the function Replace no replacements will be made.

A possible reason can be the option Whole words only. If this option is activated only content will be replaced which the program recognize as complete word. To do this there are some characters defined which lets the program knows that a word ends: . , - _ / \ € $ & ' ´ `

If you want to replace a term with one ore more of theese characters you can either deactivate the option Whole words only or click on this option by holding down the CTRL key to open a new dialog where you can define characters to belong to words.