Hi.
Very strange, never seen an issue like that yet.
Maybe you can try to update unity and Playmaker.
You can also install the latest unity version on a different location if you want to keep using your older unity version.
But before you do make a backup copy from your project.
Are you on windows/mac/linux ?
in player Settings, is playmaker included? (see image below)
You can find player setting in file/build settings, bottom left.
If all does not work can you pm me a link to your project (or the new project) or add me on collaborate so i can test on my end.