He vowed to do Hajj every year but his boss at work will not let him do that
Question

                I made a vow to Allah that I would do Hajj every year, and before that I did not have a job; then I got a job in the military and my commanding officer will not let me do Hajj every year. I hope that you can advise me whether there is any sin on me or not?.
Praise be to Allah.
    If what is preventing you from doing Hajj in some years is 
    something that is beyond you control and you cannot do anything about it, 
    then there is no sin on you, because Allah says (interpretation of the 
    meaning): “Allaah burdens not a person beyond his scope” [al-Baqarah 
    2:286] and “Allaah does not want to place you in difficulty” 
    [al-Maa’idah 5:6]. 

    And Allah is the source of strength; may Allah send blessings 
    and peace upon our Prophet Muhammad and his family and Companions. End 
    quote. 

    Standing Committee for Academic Research and Issuing Fatwas. 

    Shaykh ‘Abd al-‘Azeez ibn ‘Abd-Allaah ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan, Shaykh ‘Abd-Allaah ibn Qa’ood