Mathcad 14.0 is acting strange

I obtain Mathcad 14.0 Datecode: M020 around 2016. I haven't used it in a long time. Recently it seems to be acting sort of strange. I tried to repair it from Windows 10 Programs & Features, but it could not find a repair file.

Is there an update to my installation? If yes, where is it located?
If no, can you suggest how I can try to repair it?

Thanks