Application is not being launched correctly or not at all and this line appears in the server log.
This problem typically occurs when linking Squish to an external python or when using the squishtest module.
In both cases the underlying reason is an architecture incompatibilty.
If this occurs in the IDE, likely the architecture of the squishpackage and the external Python do not match.
If it occurs while using the squishtest module in Python, the architecture of Python and the squishtest module do not match.
Either change Python or the used Squish package so both are 64-bit or 32-bit.