...but I'd rather not have to tell everyone I share files with that they need some other version besides the most popular oneI totally agree with you.
The last 7-Zip version is 15.14 (2015-12-31)
The official 7-Zip website is http://www.7-zip.org/
Would that be usefull? I'm using 15.14 64bit as well. worth a shot I guess,Your files are OK, you are using the last official release version. In case someone has trouble downloading your file from anonfiles.com, I've made a MD5 of your uploaded file (file attached). The only different file from the official distribution, is the file "7za.exe" (may be you've copied from an older version). That file is attached here too. Anyway, all the important thing here, is you are using the last version.
https://anonfiles.com/file/c1bf374bf614b4a5eb9fc99d0f2f4deb
Maybe this error is related to Windows 10? Maybe Rejetto has only tested on XP? I don't have Windows 10 to test this. Well, if he can't reproduce your error, I don't know what else to suggest, sorry...