Receive error "We're sorry. There seems to be a problem with this file that keeps us from opening it. Please try using a backup copy if available." when attempting to open a project from Clarity after migrating from the Microsoft Project (MSP) Legacy Interface to the MSP New Driver.
This issue happens if switching from the Legacy Driver to New Driver. The error is due to a certain type of special character in one or more task notes associated with line breaks (You will see:  in the xml).
error on line 499570 at column 15: xmlParseCharRef: invalid xmlChar value 11
Below is a rendering of the page up to the first error.
3. Open the XML
4. Review the row the error is associated within the XML and you will notice the #x000B;
Line breaks aren’t able to be used with Microsoft Project XML due to a known MSP limitation with XML. The legacy driver would allow this, so that is how users were able to save projects back to Clarity and open successfully before migrating to the new driver. If a user tries to add line breaks into notes going forward, they’ll see this error: MSP Save Error: "Attempted to read or write protected memory..." due to line breaks in notes when trying to save the project back to Clarity.
So, going forward, users shouldn’t run into the "We’re sorry" error after the impacted projects have been fixed, but instead can run into the "Attempted to read or write protected memory" error if they try to add new notes to the project in MSP with line breaks and then attempt to save the project back to Clarity.
Release : All Supported
Component : CLARITY MICROSOFT PROJECT (MSP)
Clarity MSP New Driver (migrating from Legacy Driver)
See if you are able to update the task note from within Clarity to remove the line breaks:
If you get an error trying to access the notes, another option is you can delete the task and recreate it. If that isn't a viable option, please open a case with Broadcom support for assistance. (Note that if the task has actuals, you will receive an error that the task can't be deleted, but in MSP, the task will show under a "Deleted Tasks" section, and the Note should then be removed).
Important: Before deleting the task, take note of the data in the task including any dates, assignments, etc, as it will need to be recreated.
If the above isn't the cause of the issue you are seeing, see also: MSP opening projects issues - master KB
See the below for the list of known Clarity MSP Issues and Defects:
Note: for the "We're Sorry" error, removing the mpp from the prdocument table has not been known to help. See also the following KB for the impact of removing: Remove a MSP project from the prdocument table