Hello @Swar1988 there is limit on how many towns of specific type can exist on the map. If that amount is reached no more cities can be converted.
The same rule is valid for Dwelling conversion.
Set the file in MMH55_Settings.pak to a higher value. For example - 10.
On a second thought that changes only affect newly started games so it wont be of much help to you
.
Try another thing, if you are playing hotseat,
activate console and during game inside console type "H55_AmountExtraTownsDwellings = 10" without the columns.
Then try to convert the town.
Note: AI is cheating. It converts towns for free (or very cheap).