Good Luck. Only a few people play LCPDFR anymore and only one or two play who know what they are talking about.
Even though im 99 percent sure you already tried. Maybe look at this?? http://lmgtfy.com/?q=gta+4+RMN10+fatal+error+fix
Btw this error means.
RMN10
Failed to read file - Please re-boot your system