Clicking on error count on the profiles list view leads to synchronization errors view, which presents a list of all the errors for the given profile.
Errors view contains a browseable list of all the JIRA issue or TFS / VSTS work item pairs for which last synchronization failed. An existing entry for a given JIRA issue or TFS / VSTS work item indicates, that as a result of a recent synchronization failure, there are some modifications, that has not been propagated, i.e. JIRA issue and TFS / VSTS work item pair is in inconsistent state and therefore it potentially needs your attention.
Each entry on the list consists of the following information
JIRA issue key, TFS / VSTS work item id
JIRA issue and TFS / VSTS work item identifiers for which a synchronization failed. One of the identifiers may be empty, if an error occured when trying to synchronized an issue/work item that has not been paired yet (for example when creating a new issue/work item).
Last error time
The time of the last synchronization failure.
Error summary
A short error description. You can click the summary to see more details.
Operations
For every error entry there are two available operations
Acknowledge (forget)
You can click on Acknowledge link in order to ignore the error and remove it from the list. Note however, that it will reappear after the next failed synchronization attempt.
Force resynchronization
Clicking on Force resynchronization forces TFS4JIRA Synchronizer to retry synchronization at the next profile run.