Can anyone tell me what the project file size limit is for ProjectLibre?

I have just downloaded ProjectLibre version 1.5.2 and tried to open a relatively large (30,000 line / 25MB) MS Project 2010 file but it hung with the file opening green bar graph at 1/3 point.  It opens smaller MS Project 2010 project files perfectly OK.

Is this a known limit / issue and is there a work around / fix for this?

Thank you.