actually the ERRORLEVEL should work. You say it is not reliable. Which cases work and which don’t? Which operators are you using.? Maybe there is some problem in our code?
What I tried was rather simple. I had a couple of S1 files which included at least one corrupt zip file. Using a loop I read each file with gpt Read and echoed the ERRORLEVEL code afterwards. And after multiple times I could’t reliably sort out the corrupt files.
I didn’t want to spend too much time on it so I only used the one operator.