Error while adding/updating Items

I was creating a PowerShell script to add files to Shared Documents library. Everything was going fine. I was able to add files to the library but suddenly I got the below error while running the script.

It says URL “Shared Documents/new.txt” is invalid. I was looking for error in script if I had done something wrong but it was the same script that was working fine a minute ago.  Error also says “It may refer to a nonexistent file or folder” but file and folder both exists.

I was able to upload document to library using PowerShell but in different web app. Now it was confirmed that Script is fine. So error was not with Script but with something else.

I tried to add and edit items in document manually by going to Shared Document Library and I got the below error. I was getting the error while doing any CRUD operations.

On doing some testing, I found that there was not enough space on database server which was causing the issue.

So the issue got resolved by cleaning up the database server.