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InvalidTemplate. Unable to process template language expressions in action 'Send_an_email_(V2)' inputs at line '1' and column '2850': '

Hi, Morning All! 


1. When a new file is added

2. Get the file name (without extension) as email subject (with formula: 


3. Send out email.


My idea is as above and it does work at the first time. However, it suddenly not working with error below. I tried many ways as suggested to re-build a same flow and re-run or clear browsing history, both of them did not work out. 


Error: InvalidTemplate. Unable to process template language expressions in action 'Send_an_email_(V2)' inputs at line '1' and column '2850': 'The template language function 'base64' expects its parameter to be a string, an object or an array. The provided value is of type 'Null'. Please see for usage details.'.


2020-07-03 18_12_07-Run History _ Power Automate.jpg


Your advise would be appreciated! Thanks in advance!

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