Error 50: Invalid configuration file



Error 50 is a FASP error that refers to an invalid aspera.conf, which is the main Aspera configuration file. This file is responsible for configuring the transfer server, transfer users and transfer settings such as transfer policies or bandwidth caps.

This file may be invalid for a number of reasons, but the most common causes are malformed syntax, missing tags or incorrectly configured values.

Examples of this error

This error can manifest itself in several ways, including in the GUI application for your server, the command line if you’re transferring with ascp, and in the transfer log file.

GUI and ascp

When a transfer is attempted with an invalid aspera.conf, you will see the following error on the command line or in the status of your transfer in the GUI:

Invalid configuration file

Log file

The aspera-scp-transfer.log file records helpful information for each attempted transfer, labelled by the date and time attempted. For a reference of the location of this log file on your system, please see this article (Where are the Client or Server logs located?).
A sample of what would be logged for a failed transfer with error code 50 is the following:

2015-09-29 11:52:27 [7ae-0xa11541d4] ERR Invalid configuration file
2015-09-29 11:52:27 [7ae-0xb0103000] LOG FASP Session Start uuid=6fdec472-b06c-4159-9912-f9c0c2aa13a0 op=send
status=failed errcode=50 errstr="Invalid configuration"


The aspera.conf file must be well-formed in order to be valid.

Examples of malformed syntax are missing brackets or tags that are not properly closed, such as the following:


In this case the first user tag is missing its right bracket. The second user tag should be a closing tag like so: </user>

All configurations must go within the <CONF></CONF> tags--anything placed outside will cause an error.

Additionally, some tags will cause errors if an incorrect value is placed between them. For example, the <file_checksum> tag only accepts md5, sha1 or any as values, and anything else is invalid.


The best way of finding errors in your aspera.conf is to run the validation tool asuserdata. This tool will check the file’s syntax and make sure the configured values are valid. If there are any issues with the file, the tool will tell you where to find them.

You can run the tool with the following command:

# /opt/aspera/bin/asuserdata -v

# asuserdata -v

Mac OS X
# /Library/Aspera/bin/asuserdata -v


If errors are found, fix them carefully in the file. The aspera.conf file is located at the following:

  • Linux: /opt/aspera/etc/aspera.conf
  • Windows: C:\Program Files (x86)\Aspera\product_name\etc\aspera.conf (replace product_name with your installed product)
  • Mac: /Library/Aspera/etc/aspera.conf
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