Failed to load diagram

[madhurrya]

Some times when we go to instances we see this 'Failed to load diagram'
I am not exactly sure on which scenarios this happen.

1. If I change the primary bpmn file after that if I try to open an old instance it shows this error.
2. But without changing the primary file also I have noticed this. But not sure when it happens. Because if I just do some changes to the model and go to an old instance it generally works.

https://dev.mod.spiff.status.im/i/37138
https://test.mod.spiff.status.im/i/2225

[burnettk]

This happens if the git revision that was associated with the process instance does not exist in the repo. This happens when an edit is made in dev.mod, an instance is created from it, and then models are synced from dev.app to dev.mod, for example. Because there is a force push, commits are wiped out and simply do not exist any longer. Even if we wanted to fetch the diagram at that revision, it isn’t technically possible (without caching).

changing the primary file is sort of a different case. We should decide which of these two issues (if any) we want to tackle.