If a file from a disk other than the SDK disk is was opened from the Windows explorer and the SDK was located at the drive's root folder, the SDK was picked up as a local SDK and represented as a relative path, which led to a reload of the addon because the "local" path differed from the path stored in the user preferences.
SDK paths were simply compared as strings which could potentially lead to similar issues as the above.
Thanks @sh-dave for the report!