I Am Getting Error If I Execute The Below Query (The Multi-Part Identifier "Project.Project_Id" Could Not Be Bound.)

SELECT    TM_User.TM_UserID,
    TM_User.FullName,TM_Profile.Profile,TM_User.Report_To,
    Reference.lookupvalue as platform,
    STUFF((
            SELECT  ', ' + Reference_Skills.SkillLookupValue
            FROM    Reference_Skills
                JOIN TM_UserAttributeValue  ON TM_UserAttributeValue.AttributeValue = Reference_Skills.SkillLookupValue
            WHERE   Reference_Skills.SkillLookupKey = Reference.LookupID
                AND TM_UserAttributeValue.AttributeKeyType = TM_UserAttributeValue.AttributeKeyType
                AND TM_UserAttributeValue.TM_UserID = TM_User.TM_UserID
            FOR XML PATH('')
         ) ,1,2,'') as skills
FROM    TM_User
    JOIN TM_UserAttributeValue  ON TM_UserAttributeValue.TM_UserID = TM_User.TM_UserID and TM_UserAttributeValue.AttributeKeyType = 'Skill'
    JOIN Reference_Skills  ON Reference_Skills.SkillLookupValue = TM_UserAttributeValue.AttributeValue
    JOIN Reference  on Reference.LookupID = Reference_Skills.SkillLookupKey
    join TM_Profile on TM_Profile.ProfileID=TM_User.ProfileID
     join task on project.project_id=task.project_id
     join timesheet on timesheet.task_id=task.task_id

WHERE     TM_User.Is_Active=1 and TM_User.TM_UserID=13
GROUP BY Reference.LookupID, Reference.LookupValue, TM_User.TM_UserID, TM_User.FullName, TM_UserAttributeValue.AttributeKeyType,TM_Profile.Profile,
TM_User.Report_To