Error: "no valid partition found"

[feri]

Description
The format of the stick is not recognized.
This error occurrs, if an USB mass storage device is attached and the plugin can not find any partition with a supported file system.
An error massage similair to this is shown: "Internal Error reading USB Stick: class java.lang.RuntimeException - no valid partition found: ..."

How can this error occurr?
Currently the file system formats FAT12, FAT16, FAT32, exFAT and NTFS are supported. Any other format (like EXT4, HFS, ...) are not supported.
If there exist more than one partition, it is sufficient to have one partition with a supported format.
If all partitions have an unsupported format the error message "no valid partition found: class ..." is shown.
The message behind "class ..." shows the error for the first partition which could not be recognized.
In fact there exists an error message for each non-empty partition, but only the first one is printed out.

Solution:
Make sure, that the stick you attached has one of the supported formats.
In Windows you can right click on the drive and check the filesystem by selecting "properties".

Sometimes there is an error about the MBR having has wrong magic number.
This indicates, that the format on your stick is corrupt. The Plugin does not try to access sticks with wrong magic numbers.
You should fix the MBR with some partition editor (GParted?).

Sometimes there is an error about the wrong filetype.
The filetype is a hexadcimal identifier which gives a hint which format the partition has.
But it is not unique, so misinterpretation is possible.
A list can be found here:

If you need help you should activate the debug mode in the settings of the "USB-Stick Plugin-TC" App.
Then start the Total Commander,
open "USB-Stick Plugin"
and attach the stick.

The error should occurr and a detailed debuginfo is logged in debuginfo.txt.

A good example can be seen in the post from lomidze:

For each partition there is a line of output:
ERROR: read <DV01LU00P01> failed: unsupported filetype 83
INFO: read <DV01LU00P02>> unused
INFO: read <DV01LU00P03>> unused
INFO: read <DV01LU00P03>> unused

The naming is: DV<drive>LU<lun>P<partition>
<drive>: if you have an USB-Hub you can have multiple drives attached
<lun>: Logical UNit - Multicard reader have multple logical units for each card inserted. Or U3 sticks have an additional LUN for the CD-Rom drive.
<partition>: each logical unit can have multiple partitions. For USB-Sticks there is normally only one partition in use.

In the case of lomidze problem it turned out, that the first partition was formatted with FAT, but the filetype was not set correctly (83 = Linux-Format).
The solution was to reformat the Stick under Windows .

But there can be a lot of other problems.
So if you think it is a bug, that your stick is not detected, send the debuginfo to debuginfo@usbstick.hechler.de and use "question: format" as subject.

If you had any problems and found a solution for yourself, help others and post your solution in this thread.