same error ,I downloaded https://global.download.synology.com/download/DSM/release/7.0.1/42218/DSM_DS918%2B_42218.pat
and checked the sha256sum is a403809ab2cd476c944fdfa18cae2c2833e4af36230fa63f0cdee31a92bebba2
I guess it case by synology updating the pat file.
how to fix the shell ??
"sha256sum DSM_DS918+_42218.pat
a403809ab2cd476c944fdfa18cae2c2833e4af36230fa63f0cdee31a92bebba2 DSM_DS918+_42218.pat"