Hi @Doug W
I suggest you open Visio first, then go to File > Options > Trust Center > Trust Center Settings > File Block Settings > Make sure the 4 boxes are ticked as following.
Please check whether this article "How to troubleshoot damaged drawings in Visio" is helpful.
Especially refer to āMethods to try if you cannot open a drawingā, there is 8 steps you could have a try. But please remember to back your drawing files first.
Any updates, you could post back.
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