All of opensuse users know, that *.ymp files are for 1-click installations. They should not be opened as a txt file, instead - "open with" or "save as". This problem appears from the first version of new brand of opera, and never been fixed.
Try to open this file:
https://software.opensuse.org/package/opera?search_term=opera
Under Windows or Linux - the same behaviour. This is son annoying - I have to use another browser to install software in this way :(.