Invalid JSON. An unrecognized escape sequence '\T' was found in a JSON string value.

[Manc_Gurl]

I have recently starting getting the error "Invalid JSON. An unrecognized escape sequence '\T' was found in a JSON string value." on one of my flows. This seems to be intermittent, it fails sometimes.  

The part of the flow that is failing is in a send HTTP request to SharePoint action which I am using to update a document set details.  I am wondering if the T in the error message refers to my Transmittal Type field which is a choice field that I am storing the value of in a string variable.  This is odd though because it does work on some transmittals with T in the transmittal type field so I'm a bit confused.

Below is the screenshot of the send http request action

I checked the variable for the Transmittal Type after the flow has run/failed and it is stored as T so looks fine.  Not sure where to go from here

[Manc_Gurl]

Update to this, I've just noticed that the error is in fact caused by the description field, the user has entered some text with a \ between two works so I assume this is the cause.  The question is, how do I fix that so it doesn't happen in future?

[Jezter12]

Is this an option?

https://www.tachytelic.net/2020/10/remove-unwanted-characters-power-automate-flow/

[v-xiaochen-msft · Accepted solution]

Hi @Manc_Gurl ,

The backslash (\) is a special character in  JSON. JSON use it to escape special characters in strings and in order to represent a backslash correctly in strings you have to prepend another backslash to it.

replace(your string, '\','\\')

Or

replace(your string, '\','/')

Best Regards,

Wearsky