Answer:
Change concur to concurrently.
Step-by-step explanation:
The festival and the public conference will run concurrently with each other. To concur is a verb and cannot be used along with another verb, in this case the verb to run. The verb to run is the main verb and this is linked to a compound subject which has two heads: festival and public conference. The two events will take place simultneously or concurrently, therefore an adverb derived from to concur has to be used. To concur means to take place at the same time.