Upload Error Classification Labels

Hi everyone,

i try do prepare an image dataset for a classification problem. Earlier I upload a folder (per example name of the folder ‘dog’) with images and all images get the class dog. But since a few days the images get not the class by the foldername, all images are unlabeled.

I follow the instructions from the documentation Adding Data >> Classification. Have somebody the same problem or a solution for my problem?

Windows 10 Pro 21H2
Google Chrome Version 99.0.4844.84 (Offizieller Build) (64-Bit)


Hi Simon,

For the project type, did you select “Single-Label Classification” or “Multi-Label Classification?”

And when you say “since a few days,” are you saying the project had all the class names when you originally uploaded, but the same project now has all the class names removed? Or is this a completely new project?

The next question I have is: did you select “Finish Uploading” during the image import process?

I’m happy to help get this solved for you.

1 Like

Hi Mohamed,

I select the ‘Single-Label Classification’ project type and it’s a new project. I upload the images via the ‘Folder’ button, as described in the documentation (Adding Data >> Classification). I pushed the button ‘Fnish Uploading’ and the images adding to the projects but without labels/classes.

Image ‘Step 3’ shows my result after adding images to my project and the image named ‘daisy_axample’ shows the result I expect.

I create some ‘Single-Label Classification’ projects earlier and it has work fine (images get the labels like the foldername).


Did the folder have any special characters such as hyphens or underscores within it?

Additionally, I was able to find the workspace within our system and it looks like you’re on one of our Legacy “Free” workspaces. I recommend also trying in a new Public Workspace or Growth/Sandbox Workspace.

Nonetheless, I’m taking a deeper look and will file a bug report if the issue persists. Can you send a Google Drive folder with a subset of the images (or all of them) to mohamed@roboflow.com?

The folder path is ‘C:\Users\sburgdorf\Desktop\Images\roboflow\crystals’, no specials chars or blankspaces. I created a new workspace and tried the upload, but the images getting not labeled too.

Here the Google Drive link Crystals_Roboflow_Forum - Google Drive

I just tested it out and found the same error. Thank you for finding this, and apologies for the poor experience.

I have submitted a detailed bug report with a video outlining the error to our team so that we can remedy this. I’ll update you as soon as we have this resolved.

Hey @sburgdorf, I had a chance to look at your dataset and wanted to follow up with more info.

This appears to be working as expected; the way to upload a pre-sorted classification project is to upload a folder of folders named with the class you want them to be labeled with.

So, if you want these images to be labeled crystals (and presumably, you want some other class that you’re trying to differentiate between) you’d create a folder structure like this:


And this is properly parsed during the upload process like this:

That said, there are likely better bulk annotation methods we can add for classification datasets. Thank you for reporting how confusing this was; we’ll update our documentation & discuss ways we can make it more easy to use.