Error type 11 with TextOutPutStream


My web app runs fine when debugging on my Mac. Once put on my server (Linux Mint), it’s a whole different story, as it crashes.
Since I can’t debug remotely on that server, I’m trying to add a logging method to my web app. That file is created inside a sub folder (“Sample Folder”) which has permissions 777.
I use DebugStream=TextOutputStream.Create(f) and get an exception. The error code is 11. Searching over the Internet, I found 2 disappointing explanations:
•In a list of error codes, 11 means “Try again”. What should I try once more?
•Many users tell Linux doesn’t have a “known list of error codes”. It’s a mess where each developer use the values (s)he wants (what’s the point of error codes in the whole system, then?). Problem: I don’t know from “where” the error code 11 comes with TextOutputStream.Create.

I’m far, far away of making my app working, if the log file doesn’t even work…

I’ve tried showing the file’s properties (as well as the parent folder’s properties) in a MessageBox and am getting some information, but nothing relevant in the reason it doesn’t work.
I also tried setting Permissions to &o777 and the owner and group to the file, from code. The permissions seem to apply (not the user&group). Also, I’m not sure what user/group I should use.

Help welcome.