Google Colab

The file has been corrupted or is not a valid notebook file.
SyntaxError: No number after minus sign in JSON at position 1 (line 1 column 2)
CustomError: SyntaxError: No number after minus sign in JSON at position 1 (line 1 column 2)
    at new sM (https://ssl.gstatic.com/colaboratory-static/common/08e3b41ed1a5bee7e85e36cb6050fd6c/external_binary.js:2441:164)
    at va.program_ (https://ssl.gstatic.com/colaboratory-static/common/08e3b41ed1a5bee7e85e36cb6050fd6c/external_binary.js:2424:514)
    at ya (https://ssl.gstatic.com/colaboratory-static/common/08e3b41ed1a5bee7e85e36cb6050fd6c/external_binary.js:16:57)
    at va.next_ (https://ssl.gstatic.com/colaboratory-static/common/08e3b41ed1a5bee7e85e36cb6050fd6c/external_binary.js:14:195)
    at kaa.next (https://ssl.gstatic.com/colaboratory-static/common/08e3b41ed1a5bee7e85e36cb6050fd6c/external_binary.js:17:48)
    at b (https://ssl.gstatic.com/colaboratory-static/common/08e3b41ed1a5bee7e85e36cb6050fd6c/external_binary.js:17:309)