After running /scripts/fixquotas it gives following error message and showing unlimited disk space in WHM >> Main >> List account.

root@server [/]# /scripts/fixquotas –force
Installing Default Quota Databases……Done
Linux Quota Support
Quotas are now on
Resetting quota for user23 to 1000 M
edquota: Quota file not found or has wrong format.
No filesystems with quota detected.
edquota: Quota file not found or has wrong format.
No filesystems with quota detected.
Resetting quota for user2 to 1000 M
edquota: Quota file not found or has wrong format.
No filesystems with quota detected.
Resetting quota for dates to 1000 M
Resetting quota for userq to 1000 M
edquota: Quota file not found or has wrong format.

In this case refer following steps.

root@server [/]#touch /home/quota.user
root@server [/]#touch /home/quota.group
root@server [/]#chmod 600 /home/quota.user
root@server [/]#chmod 600 /home/quota.group

root@server [/]#quotacheck -acugv

Some time above command gives error message

root@server [/]# quotacheck -acugv
quotacheck: Cannot remount filesystem mounted on / read-only so counted values might not be right.
Please stop all programs writing to filesystem or use -m flag to force checking.

Than run following command

root@server [/]# quotacheck -acugvm
quotacheck: Scanning /dev/simfs [/] quotacheck: Cannot stat old user quota file: No such file or directory
quotacheck: Cannot stat old group quota file: No such file or directory
quotacheck: Cannot stat old user quota file: No such file or directory
quotacheck: Cannot stat old group quota file: No such file or directory
done
quotacheck: Checked 33478 directories and 368211 files
quotacheck: Old file not found.
quotacheck: Old file not found.

Now run

root@server [/]#/scripts/fixquotas –force

It will sort out your issue ENJOY