Hello,

You have probably the same problem as the user below.
Make sure your homepage URL ends with "/dial.html". If the URL matches the add-on URL exactly, it should be automatically cleared (empty). You can get the correct URL from the Options page / first tab / first line.

If this didn't help, please let me know to my support e-mail.

Best regards,
Juraj Mäsiar

Hello,
That option was there due to Firefox bug that got resolved in the meantime. So I removed it.
However this should not affect the URL (I mean, it can, but you should be able to fix it easily).

Just make sure your homepage URL ends with "/dial.html". If the URL matches the add-on URL exactly, it should be automatically cleared. You can get the correct URL from the Options page / first tab / first line.

If this didn't help, please let me know to my support e-mail.

Best regards,
Juraj Mäsiar

Hello,
Could you contact me to my support e-mail?
Closing browser should not disable any add-ons, this may be related to something broken in your profile. Old profiles from before 57 era are often broken in some way and it's good to use Firefox Reset to fix all profile issues. Resetting profile will preserve your passwords, bookmarks and other important things (but not add-ons data).
Before resetting your profile I would suggest you to setup Firefox Sync. - this will backup the list of installed add-ons and after reset it will reinstall them.

Best regards,
Juraj Mäsiar

Hello,
If you need assistance with restoring your data, please contact me to my support e-mail. There are ways to restore your data even without backup or cloud.
Best regards,
Juraj Mäsiar

Hello,
Please contact me to my support email.
Also please send me add-on version and your Firefox version and a screenshot would be also helpful.
Also check Options page / Thumbnails / "Auto-reload target screen resolution" - it should be set to automatic.

Best regards,
Juraj Mäsiar