Error prevents original designee from signing document

Signer received this error:

     190114084901498.app-a6

Signer is using Mac Book with Safari browser. Is this related to security settings/browser compatability? I spent over an hour in chat on Tuesday, they were supposed to contact me with an answer. No contact after 48 hours. Case Number ADB-5367272-B3X9.

Why is there such resistance to resolving errors and communicating with customers?