Be careful with old versions!
These versions are displayed for reference and testing purposes. You should always use the latest version of an add-on.
>>Andreas Wagner wrote:
>>We have been notified about serious performance issues in your add-on, apparently due to the usage of the synchronous Firefox history API. For details, >>please refer to https://bugzilla.mozilla.org/show_bug.cgi?id=1338543
>>Please add a statement to the bug as soon as possible and reply to this email. Note that we take performance issues seriously. According to our >>blocklisting policy (https://wiki.mozilla.org/Blocklisting), we might have to block this add-on if the issue is not resolved in a timely manner.