ARIMA pns model errors, which also breaks pns=0 (all) option.

[l-bailey-fnc]

Describe the bug The ARIMA (pns = 5) model errors. This also breaks pns = 0 (all).

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2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior A clear and concise description of what you expected to happen.

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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

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