There can be several reasons for this, so first of all:
- Please check if you or your author can reproduce the problem.
- Ask the person for more detailed information about the problem, for example if there is an error message.
Sometimes
the user may simply have a very bad or slow internet connection.
If that is the case, please ask the author to e-mail the file to you, so you can upload it for him or her.
For all other fixes, please go to the relevant submission type / track in which the paper has been submitted to check the settings:
Overview => Settings => Manage Submission Types / Conference Tracks- Please go to the option “Number of Uploads Required for This Submission Type per Submitted Contribution” and check the setting.
If the number of uploads is set to "0 (Disabled)", authors cannot upload any files.
Please choose a number between “1” and “3” to enable uploads (see image).
Have a look at more background information here: Uploading two (or more) files for each submission - Please check the option(s) "File Extensions for File No. X” to make sure that this option is configured correctly.
In order to make sure that the file type is accepted, you can simply choose one from a list that is provided when you select the link "Select file types from list" (see image).
You will find more information about file types here: File formats for paper uploads - Further upload settings for uploads might be enabled. Those might keep the author from being able to upload a file.
Please activate the expert settings on the bottom of the page first.
Then go to the option(s) “Upload Options for File No. X” and check the settings (file updates might be locked, only file updates might be allowed, the slot might be closed altogether; see image).
You can find more information here: Using ConfTool to upload presentations shortly before the conference
Please
test your settings, i.e. carry out a test submission:
How can I test the settings?
ConfTool Support Forum
Topic: Upload of file for submission seems to be impossible