Air project ADT error : "Could not apply timestamp to setup.msi"

I have a problem with ADT to create air package from an AIRI intermediate package.

The ADT command I use worked well for a long time until a few weeks ago. Now, when I launch ADT, the certificate signature and timestamp seem to work but at the end I get this message

"Could not apply timestamp to setup.msi". 

Here is the ADT command :

adt.bat -package -storetype pkcs12 -keystore newcert.p12 -tsa "http://sha256timestamp.ws.symantec.com/sha256/timestamp" -target native -storetype pkcs12 -keystore newcert.p12 "myProject.exe" "myProject.airi"

I tried with Flex SDKs 4.6.0 and 4.12.0. Same error. Java 1.8.0_65.

Any help would be so appreciated ... Thanks.