Phab:rP24411, Phab:rP24414, Phab:rP24194 removed the differencr between terrain ambient colors and unit ambient colors to allow for future optimizations of the renderer. Phab:rP24661 removes the option breaking the loading of maps therefore required an increase of map version.
Phab:rP24653 increases the version to 7. You will need to run the following script on all your maps.
Fortunately you can use the script at Phab:P232 to fix all your maps.
We need those changes to be able to use PBR someday amongst other things.
You need to have Python 3 (there is a chance that it works for 2 as well) installed to run the script.
Go into your map folder
Create a file named "fix-maps.py" (name does not matter)
Copy the contents of Phab:P232 in that file.
Open a command line or a terminal in that folder
Run
python3 ./fix-maps.py 7 scenarios skirmishes tutorials