I believe we addressed this in r35551 (ee048d5) and r35552 (7300cde):

o [Nsock] Avoid a crash on Windows and other systems which use nbase's vasprintf implementation. In the case of unknown OpenSSL errors, ERR_reason_error_string would return NULL, which could not be printed with the "%s" format string. Fixed by using ERR_error_string instead, which will not return NULL, and by causing NULL pointers to be printed as "(null)", as glibc and MSVC both do. Reported by Dan Baxter. [Gisle Vanem, Daniel Miller]

I will keep looking at it to see if there's an NSE-only workaround to restore functionality without rebuilding a new installer for Windows. In the meantime, you may try disabling the mrinfo script by adding "and not mrinfo" to the --script option: --script "default or (discovery and safe) and not mrinfo"

I think this issue can be closed. AFAICS, the r35552 fixes this bug.
@Rewt0r can you confirm?

Is that part of 7.01 or do I need to use another release from somewhere else?

@Rewt0r The fix mentioned here was released with Nmap 7.10 in March 2016. The latest version is Nmap 7.12. Does this version work for you, or are you still having problems? We would like to close this bug if it has been fixed.

Closing, assuming this is resolved.