You might run into an extended Calculating message in your doc. It looks something like this:
While it's normal to see this on large docs, or docs using some Packs, occasionally seeing this message for a prolonged time may be indicative of the design of your Coda doc. Check that your doc doesn't have any of the following issues:
Formulas in Coda can be used to model complex relationships, but occasionally a formula you rewrite can lead to unbounded recursion, (e.g. when a column formula causes a different column to depend on itself, which in turn depends on the other column, which in turn depends on itself, etc.). Coda's formula engine detects a number of these "infinite loops", but with some indirection it's possible to get around that, which leads to a perpetually calculating doc.
You can usually resolve this issue by removing or adjusting formula. In some cases where that's hard to do, create a copy of your doc from an earlier version using revision history, or contact us to help revert your doc on our end. Our automated systems may also detect this case and we may contact you to address the issue.
Packs in Coda can be great for pulling in external data into your doc, but there is a caveat: these are generally third-party services that may from time to time be unavailable or very slow (especially if your doc is computing the value of a Pack formula many times).
First, check to see that you're not fetching data that you don't actually need. For instance, suppose you have a doc that periodically updates Pull Requests from GitHub using an Automation. If you only really need to see activity from the last week, consider cleaning up old rows weekly (or writing an Automation to do it for you) to help prevent your doc from getting slow over time.
Second, if your doc is stuck calculating even with a small dataset, make sure that the service isn't down. For example, GitHub has a status page that is kept up to date with service disruptions. Since Coda Packs use these same services, the availability and performance of Coda Packs is highly tied to the third party.
If you're still having trouble, please don't hesitate to reach out to us for help.