[ERR_INVALID_CALLBACK]: Callback must be a function

[moharm]

i use jquery-file-upload-middleware to upload my images to the server but it's crashed everytime !!
this my config:

upload.configure({
uploadDir:'./store/test',
uploadUrl: '/store/test',

})
app.use('/toto', upload.fileHandler());

in the front:

** the picture is uploaded but the app crashed and this is what i get :**

fs.js:136
throw new ERR_INVALID_CALLBACK();
^

TypeError [ERR_INVALID_CALLBACK]: Callback must be a function
at makeCallback (fs.js:136:11)
at Object.unlink (fs.js:938:14)
at ReadStream. (D:\disktop\Stage 2\gestion d'absence\projet\node_modules\jquery-file-upload-middleware\lib\uploadhandler.js:149:48)
at ReadStream.emit (events.js:194:15)
at endReadableNT (_stream_readable.js:1125:12)
at process._tickCallback (internal/process/next_tick.js:63:19)

[hungvuongwork]

Hi there! I follow this path:
\node_modules\jquery-file-upload-middleware\lib\uploadhandler.js:149:48
, after that I found solution here:
https://stackoverflow.com/questions/53583183/i-have-got-typeerror-err-invalid-callback-callback-must-be-a-function/53591136

I changed this unlink to unlinkSync. It worked!
if (!err) { **fs.unlinkSync(file.path);** generatePreviews(); }