On Firefox 43 and later you need to set `xpinstall.signatures.required` to `false` via `about:config`, to try such unsigned packages of development builds.
For Firefox 46 and later, you'll have to try an unbranded Firefox (including Beta, Aurora, and Nightly) to try development builds because the option will be removed on official Firefox 46 and later.
You can start Firefox with temporary clean profile by a command line `-profile`, like: `"C:\Program Filex (x86)\Mozilla Firefox\firefox.exe" -no-remote -profile "%Temp%\FirefoxTemporaryProfile"`
Then, please report the bug with these information:
If the problem appear on your multiple platforms, please list them.
## Feature requests can be tagged as "out of purpose"
Please see [the readme page](./README.md) before you post a new feature request.
Even if a requested feature is very useful, it is possibly rejected by the project policy.
Instead, please tell me other addon which provide the feature and report a new issue as "compatibility issue with the addon, TST should work together with it".
For example, if you hope to fix an exsiting typo in a locale, you just have to click the pencil button (with a tooltip "Edit this file") for a language resource file.
