V5 installation

I just recently tried to install V5 of bricscad and received the following error.crc error: The file c:\program files\bricscad\R18toR15.dll doesn't match the file in the set-up's .cab file. The medium from which you are running the setup may be corrupted; contact your software vendor.I hit ignore and the software continued installing. I was wondering if the file that I have is corrupted or if that file isn't necessary. The software works, but I don't want to run into a problem down the road because that file wasn't installed properly. Thank you.