Screenshot of error
When using the Wikimedia Commons Upload Wizard today I got the error <api-error-stasherror> listed for each file when it came to adding the files (the stage after adding descriptions).
I was trying to add 5 files, and adding each of them to a new category as well as two other existing categories. The files are all jpeg images, around 40-100kB in size.
Browser is Google Chrome 29.0.1547.66 m
T56460: Missing message <api-error-stasherror> in connection with the UploadWizard