kINDLY EXPLAIN SOMEONE HOW TO RESOLVE THIS ERROE

The error says that no gas phase species is specified.

Well, the thing I am trying to do is to make variable density of phase one but this is not working and this error is now displaying:

Error 1101: No solids density information for phase 1.

Anybody have solution of it?

From the first screenshot, it looks like you didn’t define a valid baseline composition for phase 1. The sum of species mass fractions must add up to one (see the red 0.6 showing the sum)