Good afternoon,I applied for change of employment...

If you have applied for a notice to end your work relationship and the application was canceled, and you wish to know the reason behind that, so you have to refer to the Ministry of Labor, and usually, the cancellation is because that the notice period is not sufficient. Therefore, please find the Labor Law article that stipulates:
Article 39
The work contract may stipulate that the worker be put on a probation period that is agreed on by both parties, provided that it shall not exceed six months from the date of commencement of work. The worker may not be assigned on probation more than once with the same employer.
The employer may terminate the work contract during the probationary period if it appears to him that the worker is not fit to perform the work, provided that he informs the worker of this, at least one month prior to the date of termination of the contract. The worker may terminate the work contract during the probation period, provided that the following are taken into consideration:
1 - In case that the worker wishes to transfer to work for another employer, he must notify the contracting employer in writing of his desire to terminate the contract at least one month before the date of termination of the contract, and the new employer is obligated to compensate the contracted employer for the value of the ticket and recruitment fees, If any, provided that the compensation does not exceed the basic wage of the worker for two months.
2- In case that the worker wishes to terminate the contract and leave the country, he must notify the employer in writing of his willingness to do so in accordance with the agreed-upon notice period, provided that it does not exceed two months.
If either party terminates the contract without observing the notice period stipulated in this Article, it shall pay the other party compensation equal to the worker's basic wage for the notice period or the remaining period thereof. In all cases, if the expatriate worker leaves the country without being bound by the provisions stipulated in this article, he may not be granted a work permit for one year from the date of departure.