I am using ArcGIS 10.5, and I need to frequently save MXDs as 10.4. It would be nice to be able to use this tool (How To: Save map documents in ArcGIS 10.x to previous version of ArcGIS in batch ) be able to batch process. I set up the script, but it does not work to save as 10.4. I can save as 10.3 and earlier, but it would be so much easier and cleaner if I was able to figure out whey this doesn't work for 10.4. It tells me that my MXD is originating as 10.4, but I even saved a brand new clean document in 10.5 and I get the same error:

Has anybody figured out how to use this tool to save 10.5 MXDs as 10.4 MXDs?

Thanks.

Read the error you will find the answer.

Value Error: Invalid value for version u '10.4' ( choices are: [ '10.1' ,'10.0' , '8.3' , '10.3' , '9.0' ,'9.2 ' ,9.3'])