Are you able to edit the fields directly in the Query?
Can you post a screenshot of your query in Design View?
Not Updateable

no, I cannot edit the fields in the directly in the query either.

is it an Aggregate Query?

Juan, it is not an aggregate query.

I have tried to change the join types and that doesn't work.

Can you show a picture of the query in table format? Can you add new info at the bottom?  I am trying to drill down the problem.

Sorry I ment to say Data Sheet view.  I like to see if you can add a record.

Juan, No I cannot add a record in data sheet view either.

You may have to break the Query into several smaller Queries.
Or perhaps change your joins.
Have you tried taking both joins from Primary Key in the main table to the Foreign Keys in the supporting tables?
May not work - just brainstorming.

I changed the links and order of tables around and I can now add a record in the query and modify a field.

Yep, thanks Kevin, we were on the same page.