(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?
(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.
The answer to this question depends on who's responsible for the risk of each delay. If the client has some responsibility for one of the delays your are looking at a concurrent delay situation, if the contractor is responsible for both, the contractor has a problem.
Concurrent delays are a complex issue affected by the contract and by diffeent interpretations of law in various jurisdictions see: https://mosaicprojects.com.au/PMKI-ITC-020.php#Concurrent