I do have the issues with 2 mentioned functions above.
!log %dirpath() -> [Log]
path could be derived on my machine, no string [Log] output
!log %file_exists("c:/foo/dummy.txt") -> [log] 1
!log %file_exists("dummy.txt") -> [log] 0
Info1: other Builtin functions are working well e.g. %filename or %date.
Info2: If I pass the absolute path return value of %file_exists is true as expected
Info3: files dummy.txt and PlantUML.puml are in same folder "foo"
Info4: Description of Builtin functions: https://plantuml.com/de/preprocessing#291cabbe982ff775
Thanks in advance