I have tried that also and tried to delete that KB and make a new one still it's not getting indexed, As per your que.. At first I upload 30 PDFs than out of 30 , 5 was not getting indexed, so I reuploaded them and they got indexed perfectly but when I go to my 2nd KB for start the indexing of other 25 to 30 PDFs than out of 30 not a single started indexing, after that I guessed that it needs time so I wait for 4 hours and it's still written as "Created 4Hours Ago" below the file