My update would proceed until the "Applying Differences File" stage at which point I would get the oh-so-unhelpful NullReferenceException error. Lingo would then report quantities of new and changed files but not actually apply the changes.
This Lingo project was configured to use a specific Flare target at the project level and I managed to get by with the following work around:
- Open the Project Properties.
- Select Flare Settings.
- Set Filter by Target to All Targets. Note this will cause translation statuses to reset.
- Click OK and allow the Lingo Project to Update.
- Run Update Project.
- Set Filter by Target back to the desired Target. Note this will cause translation statuses to reset.
- Click OK and allow the Lingo Project to Update.