Hi HomerJ,
As found within knowledge document KM02863020 as put out by Microfocus, the digital certificates were changed for ALM 12.55 and will need to be updated and applied for the clients systems.
This is from Microfocus regarding the new certificates:
In ALM 12.55, we introduced a new timestamping CA - GlobalSign. To have the ALM client downloaded and installed correctly, we need the client machines with the root certificate of GlobalSign installed.
In addition, Verisign is also used for some files. It should also be installed if the client machine doesn't have it.
Fix
Download and import the certificate from https://support.globalsign.com/customer/portal/articles/1426602-globalsign-root-certificatesusing certmgr MMC.
Download and import the certificate from https://knowledge.symantec.com/support/ssl-certificates-support/index?page=content&actp=CROSSLINK&id=INFO4159#lightbox-06 using certmgr MMC.
I hope this helps with your issue,
Dan