Approver receive an email with link to a workflow task, and got an error message: Sorry, Something went wrong. An unexpected error has occurred. Web Parts Maintenance Page: If you have permission, you can sue this page to temporarily close Web Parts or remove personal settings.
Instead of an error, the user was supposed to see a custom task form to select "Approve/Reject." So now, clicking on the link takes me to the Web Parts Maintenance Page. There was a ListItemWebPart and I closed and then reset it, but neither fixed the approver's error message. When the web part was closed, the workflow task page is blank. Note: when the web part was "closed" I was able to restore it by adding it back from the web part list.
So, thinking the web part only applies to this list and closing it didn't fix the issue, I deleted it. And now all hell breaks loose. I cannot recover the web part anywhere. And ALL lists under the same site now cannot access the approver's task page. The workflow task page is blank.
Note: Here's the error message shown on workflow task history - "Error in task. Object reference not set to an instance of an object." and here's the URL that goes to the task form: /Lists/Workflow%20Tasks/EditForm.aspx?ID=
If anyone has any insight on this, please do share...I have not been able to find much on this let along the same case scenario.