the sentence after ”after”

你o個冇問題。
Buckingham Palance (Subject) complained (verb) to the Press Complaints Commission (indirect object) about the August 6 front-page story (direct object)
after 後一係用個名詞，一係完整句子：
I met her after dinner.
I met her after I had dinner.
留意，呢句中，after 之後o個件事唔會因事發先後變 past tense：
I will meet her after she comes.

After can be used as a preposition as well as a conjunction. Thus, when it is used as a conjunction, the word can be followed by a complete sentence. For example:
John arrived at the station at 8:30.
The train left at 8:27.
=> John arrived at the station after the train had left.
=> John arrived at the station after the train's departure.

The sentence "Buckingham Palace complained to the Press Complaints Commission about the August 6 front-page story" is a complete sentence.

The structure is: X complained [to Y] [about Z]
Buckingham Palace -- subject (X)
complained -- verb
to the Press Complaints Commission -- indirect object 1 (Y)
about the August 6 front-page story -- indirect object 2 (Z)

應該改成 Buckingham Palance complained to the Press Complaints Commission about the front-page story on August 6.

the sentence seems correct but i think it would be better if u switch it to 'about the front page story on august the 6th!