Unable to create TO for articles in Return delivery

Dear All,

For a return delivery created against a PO, I am not able to create a TO to a specific storage bin with the below error.

Storage type 007 does not allow negative stock figures

Message no. L3037

I do not understand why system considers this stock as negative stock and would like to if there is anything wrong in the settings or process followed here.

I have gone through many posts in SCN but could not relate any of those to this scenario.

I checked the stock of bin and could see that all the articles included in the bin have stock category S(blocked stock).

Please let me know if this has anything to do with the above error message received while creating TO

Regards,

Manasa