Answer:
The sentence above has no independent clause. It is an ungrammatical sentence.
Step-by-step explanation:
The sentence above is introduced by the subordinating conjunction "although". Consequently, this subordinating conjunction introduces a dependent clause, a clause which can't stand on its own as a complete sentence because it does not represent a complete thought. It lacks the independent clause to complete its meaning, it relies on the independent clause. Complex sentences must contain one independent clause and at least one dependent clause but the independent one must be there.