I'm a fellow FM user and I ran into this problem as well with the error; "Can not write file to the external storage" message. I'm not sure where to go with this issue. I've look in the forum and check other places, but just can't get my arms around this problem. Can someone help me out with this issue?
The problem is that, once I try to drag a document or PDF file into the container field I get the coffee cup and then the "Can not write file to the external storage" message.
My setup is: I have a field called; "Attachments" the type is (Container) and for the Options/Comments (External (open)). All documents, PDF files, images and etc... are stored in this path location ("Main Table 3/Attachments/").
What can I do to fix this problem?
Thanks in advance!