re: â€¦Yesterday I added a rendering flyout to the Standard toolbar. Today I opened TC18 and it is not there; but there are some other changes I made that are there.
I've run into this on a rare occasion, but usually some fatality had struck the program during that time.
Yes, you should save your changes. As WD pointed out, go to the "Tools / Customizeâ€”â€ºOptions" page, overwrite the current Workspace in the "Save In" list with a name of your choosing. Never save to any of the supplied workspaces. They're replaced any time you reinstall or update. Click on the "Save In" button after entering a unique name. If you start TC and something is amiss, choose your saved Workspace from the "Load From" list, then click on the "Load From" button. Once a Workspace is loaded, it should remain like that. Things that may also cause glitches is running two or more instances of the same TC version or shutting down TC in a minimized state. I sometimes may find TC is still listed in the Task Manager "Processes" section, even though it's nowhere to be seen.
Designer, Deluxe, (Professional, Expert, Basic), Platinum
Windows 10 Pro (1903), 64-bit