Node type 0 (zero)

I am updating my module from 4.6 to 4.7. It was stable at 4.6 and fully functioning.

Now, using 4.7 platform and i've updated the module, but when I go to add a "node" using this module, I see the form, but when it comes to submitting it:
- The confirmation doesn't recognise the content type: "Your was created."
- The data is not added to the module's tables
- In "node" table, the row is added but for "type" field it says "0" (zero)

It shouldn't be the database issue because my other similar modules work, after update.

Any ideas?