English question

Though the use of singular and plural in the same agreement is acceptable, it's likely just a simple error, either in translation or in the original text.

Many (often larger) agreements contain phrases that address the interpretation of the agreement. One of those phrases says that where the agreement is stated in the singular, the obligations should include the plural (and vice versa). Even though an agreement should be interpreted as a normal and reasonable person would read it, some drafters believe that a normal and reasonable person could say (after reading a contract provision that talks about one person required to do or omit something) that the contract provision does not apply to cases where two or more persons would omit or do what is written in it.

This can be confusing, but the use of the plural (obligations) can be used in case TWO contracted persons fail to carry out their separate obligation. Each separate obligation amounts to two combined (plural) obligations.

It is probably only a simple mistake.

Though whether a barrister in a court of law might pick up on it and savage the failed party's representative over previously-unidentified "obligation[i]s"[/i], in cross-examination, is another matter!

Maybe it is referring to certain duties here to to show the importance of party’s performance.