What is the collective nouns for problems?

There isn't one universally accepted collective noun for problems. Here are some options you can use, depending on the context:

Formal:

* A plethora of problems

* A myriad of problems

* A constellation of problems

* A cluster of problems

* A web of problems

Informal:

* A bunch of problems

* A heap of problems

* A mountain of problems

* A mess of problems

You can also use a noun that describes the specific type of problem, such as:

* A string of grievances

* A storm of complaints

* An epidemic of errors

Ultimately, the best collective noun for problems will depend on the specific situation and the tone you want to convey.