Hello. Thank you for contacting the Toolset support.
Before you update the Toolset plugins to latest official release version:
*** Please make a FULL BACKUP of your database and website.***
For now, please try to update the Toolset Types plugin manually from plugins page and then you can add/update addon Toolset plugins:
- Deactivate and Delete all Toolset plugins from plugins page
Thank you but that still doesn't answer my main question: why am I not receiving notifications that the plugins need updating?
==>
You are using really outdated plugin version that is one of the cause and with that version we had a issue as well.
Once you update all Toolset plugins to latest version you will be able to start receiving update.
I have to install this OTGS installer? Is that a new thing?
==>
No, you just install the Toolset Types plugin version that is it and try to register the Toolset plugin.