Hi @SM123 

if you can share the error message here that would be great.

most likely if you access to the SP server, then you can look at the ULS log on the SharePoint hive and explore the Logs using the “ULS Viewer” look for the SPTimer.exe most liklly the SPTimer in your server have an issue.

i would suggest the following:
 

It might be a performance issue
Please provide the following info:
 
1.  how many items are in your 'NintexWorkflowHistory' lists?  (should be under 5,000 items)
Navigate to Http://SiteName/Lists/NintexWorkflowHistory and check how many items are present.
or 
go to Site Settings --> find a Nintex Workflow group -->click on the "Manage workflow history lists" link
 
2.  How many workflow tasks are in the Task List this workflow utilizes?  (should be under 5,000 items)
Navigate to the task list your workflow/task action is configured to use and check how many items are present

3.  How many rows are in your 'dbo.WorkflowProgress' table in your Nintex Workflow databases (SQL)?  

Thanks,Majid
 
5.  Also, please create a and run a simple workflow test on the same SiteCollection : and provide us with the result.
- using Nintex workflow : START -> Log history -> Pause 5 min -> Log history -> END     save/publish and run, does it run and complete within 5 min?
- using SharePoint Designer workflow (SPD) : START -> Log history -> Pause 5 min -> Log history -> END     save/publish and run, does it run and complete within 5 min?

Also, would you be able to check How many items are in the SharePoint table ScheduledWorkItems] ? this table should be in the SharePoint content DB.
 it might be that the SPTimer job is so busy processing this job queue when it comes to processing a workflow with Pause action.
  

Hi @SM123 
Has this issue been resolved?