Is Verify Disk in the Disk Utility missing in High Sierra?

Might try Terminal, here's Verifying an external volumes called FireCuda...

cd /Volumes

ls

Elite2TB1 FireCuda

diskutil verifyVolume FireCuda

Started file system verification on disk1s2 FireCuda

Verifying file system

Volume was successfully unmounted

Performing fsck_hfs -fn -x /dev/rdisk1s2

Checking Journaled HFS Plus volume

Checking extents overflow file

Checking catalog file

Checking multi-linked files

Checking catalog hierarchy

Checking extended attributes file

Incorrect number of extended attributes

(It should be 1936771 instead of 1922870)

Incorrect number of Access Control Lists

(It should be 1070870 instead of 1070438)

Checking volume bitmap

Volume bitmap needs minor repair for orphaned blocks

Volume bitmap needs repair for under-allocation

Checking volume information

Invalid volume file count

(It should be 1945302 instead of 1957752)

Invalid volume directory count

(It should be 417565 instead of 420160)

Invalid volume free block count

(It should be 129050354 instead of 128385658)

Volume header needs minor repair

The volume FireCuda was found corrupt and needs to be repaired

File system check exit code is 8

Restoring the original state found as mounted

Error: -69845: File system verify or repair failed

Underlying error: 8: Exec format error

Hey there Girshon Rutstein,

Thanks for reaching out to Apple Support Communities. Are you attempting to repair your disk through macOS High Sierra? If so, take a look at this helpful article:

About Disk Utility

Have a great day!