I have a python toolbox I was working on in 10.2 version then recently upgraded 10.5.1 version. Now there is a red "x" icon on my python toolbox. How do I fix this?
depending on where you put the toolbox, it could be gone.
Use File Explorer and just do a search for " .tbx " dot in front of the tbx no quotes
You will get a listing of the system toolboxes and any user toolboxes stored elsewhere.
And for the future, it isn't a good idea to store your toolboxes where software installation/updates can get rid of them