Hi there,
I downloaded your module zip file from github and I would be happy to test out your module but on my PS 1.7.8.8 it always shows "Oops... Upload failed" pop-up.
The popup appears both on my test env where I have debug mode enabled and live env where no debug is enabled.
this is the detailed popup output:
I also tried by renaming vatchecker-master.zip to vatchecker.zip but same result.
Any help would be appreciated.