There’s two problem in your site:
One of your plugins or theme uses a lot of memory, HMWP uses RAM more than simple plugins but it didn’t cause this problem. You correctly increased Max memory to 256M but I still see error message . If it’s not a popular website with thousands visitors per day you should seriously find that plugin (or theme!).
Note that usual WP installs consume around 30~50 MB of RAM so there’s a big gap here. You can also use cache plugins to solve the problem but I suggest to find the reason first. There are some plugins that display memory usage in the footer of the source code (2012 theme also has this feature). Use them and activate, deactivate plugins and see the differences.
In case of HMWP, the problem is that one of your plugins change htaccess badly so it conflict with HMWP. I changed htaccess (duplicate problem) and it works correctly but the other plugin change htaccess again. Therefore you should also find that plugin and disable it (or maybe find another alternative).