Hi @MochAlex 

Could you provide additional information to help narrow down the possible issues?

Has the workflow ran successfully previously?

What kind of of list (Document library, List, subsite) ?

How many items are on the list? over 5,000 items?

If you created another subsite, and imported the workflow, will the workflow run?

If you created a new workflow with 1 sendEmail, will it run?

any other useful information?

Hi Garret. Yes it works previously (yesterday). I have lot of Subsites, but today the workflow can not be launched in only 1 subsite, let says "Subsites A".

This subsite has more than 5 lists (I use Nintex Workflow). All the lists fail to launch the workflows. I've created very simple Nintex Workflow (notification email), and the workflow still can not be launched / run.

I'm quite sure if we make a new subsite, and reimport the workflows, it will run. But I think that's not the solution, because we have lot of running workflows in this subsite.

You should raise a ticket with Nintex Support.

Since the workflow was working previously and today it is not working.

Furthermore new workflow cannot launch/run from the Site/List

There isn't sufficient information to pinpoint where the fault occurs.

Did any changes occur to the site since yesterday?