Updates broke my client's website by adding the prefix. Default should have been to have no prefix and big warning prior to adding one. Instead you chose to add a prefix where one wasn't required previously. Keep in mind that some of us are actually trying to make a living developing web sites and cant' afford to have inconsiderate and obviously poor design break the site immediately upon updates. In addition, the short code generator is broken as it just spins without generating code, etc. The reminder to add a review and to otherwise rate the plugin is broken also as it does't stay dismissed.
Here's the link to version 3.9.5 which works for me:
[offsite link redacted]