I think @Omar_AlSuleiman said is correct. It would be definitely the selector issue. As per the query it is not identifying the text so mostly there would be some attribute in selector which are changing Everytime when the webapp is opened. So find that one make it dynamic by using wildcard symbols
Or to identify the uielement u can also go with css selector too
Hope it helps
Regards
Nived N 
Happy Automation 
