Optisystem 13 Cracker
OptiSystem 13 includes many important enhancements including several additions to the toolkit for building higher order modulation and Nyquist-based transmission system designs, new components and models for analyzing the impairments/limitations associated with high speed transmitter and receiver.
It is possible that your PC has been registered in their database as having been used to run a trial version before, and hence no further trial period is granted for that particular PC. You may also have been sent a trial code to your email address, so that you can not active a new trial using the same email address.
Optisystem 13
Optisystem 13 Cracker House
I guess you can try to install the product on a different machine or get a new trial code sent to a different email address. In essence the software is probably working as expected with regards to the trial period, but you didn't get to finish your testing phase within the time limit.