Sometimes, if not usually, Windows errors’ messages are not informative !
A user reported to me that he can’t save his PDF document to My Documents folder. When clicking on the save button he get this message “Unable to save document. An I/O error has occurred“. Thank you Windows for this message !
What I did, is to run Process Monitor, of SysInternals Tools, and record a trace when saving the PDF documents…
Process Monitor has an interesting tool, I use often, called “Count Occurrences“. It lists all the columns of the Procmon interface and when you choose a column it will show you all the values contained in this column.
I selected “Result” in the column list. In the shown values, there one the caught my attention; Disk full !
I double clicked this value, to apply a filter…
You can see that the My Document folder is redirected to a network location. There was quotas applied to this folder on the file server and this user reached his maximum allowed storage size.