i-Diario-App (SyntaxError: Unexpected token < in JSON at position 0)

Realizei a instalação do sistema em i-Diario-App em Ionic e estou tendo o seguinte problema, alguém sabe como resolver ou já teve o mesmo erro e pode me ajudar?
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SyntaxError: Unexpected token < in JSON at position 0
at JSON.parse ()
at Response.Body.json (localhost:8100/build/vendor.js:59289:25)
at MapSubscriber.project (localhost:8100/build/main.js:3911:29)
at MapSubscriber._next (localhost:8100/build/vendor.js:51457:35)
at MapSubscriber.Subscriber.next (localhost:8100/build/vendor.js:20701:18)
at XMLHttpRequest.onLoad (localhost:8100/build/vendor.js:59789:38)
at t.invokeTask (localhost:8100/build/polyfills.js:3:15660)
at Object.onInvokeTask (localhost:8100/build/vendor.js:5076:33)
at t.invokeTask (localhost:8100/build/polyfills.js:3:15581)
at r.runTask (localhost:8100/build/polyfills.js:3:10834)

Segui as sugestões e o erro prevalece

O erro ocorre no navegador?

ERROR SyntaxError: Unexpected token < in JSON at position 0
at JSON.parse ()
at Response.Body.json (vendor.js:59338)
at MapSubscriber.project (main.js:3952)
at MapSubscriber._next (vendor.js:51506)
at MapSubscriber.Subscriber.next (vendor.js:20750)
at XMLHttpRequest.onLoad (vendor.js:59838)
at t.invokeTask (polyfills.js:3)
at Object.onInvokeTask (vendor.js:5125)
at t.invokeTask (polyfills.js:3)
at r.runTask (polyfills.js:3)