Unable to delete an attachment or set a preview picture for a task

[Mohan Kumar Narayanan]

I'm unable to set a preview for attached document on a task or delete an attachment from a task. 

When I hover over the attachment, it does not give me the 'Show on card' checkbox or (...) button next to the attachment.

[#2]

From your screenshot it seems that attachment is not uploaded. Once the upload is complete, you will see those options. Also note that you cannot delete the attachment from task, it can only be removed. If you need to delete the the attachment you need to visit the plans relevant SharePoint.

[#3]

Thanks for your reply. 

I missed to see this the below error when I tried earlier.  However if I upload the files in the 'Files' section of the plan and give link I'm able to see those options. Not sure what the issue.