I ran into this problem and found nothing via search so I'm sharing the "fix".
If you pin putty portable to the start menu on windows 10, then use the "recent sessions" or "pinned sessions" that can cause this error if the saved session doesn't exist in the registry.
I originally thought it was a conflict when you have the non-portable version installed on your PC, but that's not correct. I uninstalled my local version and it had no impact.
What I did was:
* Have the non-portable version installed on my PC.
* Have "website1name" as a saved session.
* Imported my settings to putty portable https://portableapps.com/node/60898
* Was using "pinned sessions" via the windows 10 start menu.
* Changed the name of my saved session to "website1newname"
This results in the "PuTTYPortable\Data\settings" directory having the new name, and the "HKEY_CURRENT_USER\SOFTWARE\SimonTatham\PuTTY\Sessions" keeping the old name. This causes the error.
If I launch with "website1name" instead of "website1newname", or if I manually open putty-portable (not just the shortcut) and then load the session, then it works.
An "easy fix" is to run the putty.reg file at "PuTTYPortable\Data\settings", which will overwrite (or add to) the settings (in the registry) of your installed version. There may be some cases where this isn't desirable though (IE: using someone else's computer). I'm not sure if anything can be changed to make it work.
Windows doesn't understand apps that require multiple EXEs to run like with our PuTTYPortable.exe launcher, so it just runs putty.exe directly in local mode when you pin an app via Windows. To properly pin a dual EXE app, use the PA.c Platform. The apps tell the platform how they can be pinned and the PA.c Platform helps you pin them properly linking to the PuTTYPortable.exe launcher but with the appid of the base app so it doesn't show as two separate taskbar icons when running.
Sometimes, the impossible can become possible, if you're awesome!
What is PA.c? Oh portableapps.com? That's what I did. That still results in this error/bug.
I didn't pin to taskbar though, I pinned to the start menu.
You right-clicked it in the platform and selected Pin To Start and then followed along the instructions?
Sometimes, the impossible can become possible, if you're awesome!
"Add to start programs", yes.
Often I use "Pin to taskbar" (which I haven't noticed any issues with) but didn't for this. I suppose that might be another "fix"?
What do you mean by 'pinned sessions'?
Sometimes, the impossible can become possible, if you're awesome!
When you "mouse-over" Putty portable when it's on the start menu, it has an > that leads to "recent sessions", "tasks", and if you pin one of the "recent sessions" then there's a "pinned". The issue will occur for either "pinned" or "recent sessions" that don't exist in the PC's registry.
I'm not seeing this. I use PuTTY regularly and have it pinned to the Windows 10 Start Menu. I see no such option when mousing over or right-clicking. Is this something you need to manually enable?
Sometimes, the impossible can become possible, if you're awesome!