[Sentry] Error: Invalid chain ID "null"

[sentry[bot]]

Sentry Issue: METAMASK-MOBILE-3SBE

Error: Invalid chain ID "null"
  at ResultError (ses.cjs:7676:17)
  at _isSmartContractAddress (app/util/transactions/index.js:395:42)
  at isSmartContractAddress (app/util/transactions/index.js:376:45)
  at _ref3 (app/components/UI/AddCustomToken/index.js:365:37)
  at validateCustomTokenAddress (app/components/UI/AddCustomToken/index.js:388:4)
...
(45 additional frame(s) were not displayed)

[dan437]

It's triggered from transactions utils, so I'm assigning it to the Confirmations team. The util file was called from adding a custom token UI.

[cryptotavares]

Assigning to Assets team, as the issue seems to come from the AddCustomToken component.