seen under the solution explorer I see a warning sub-icon on the Dependencies/COM for a key and anytime the project is opened I see this warning: warn: Cannot access project reference path. Is "{bee4bfec-6683-3e67-9167-3c0cbc68f40a}" reference valid? Reloading project might resolve this issue.
reloading does not seem to help and other threads on Stackoverlfow have addressed this but their solution do not seem to apply or work, so I'm guessing this is an idiosyncratic matter. I see this key in a number of places in the registry under HKEY_CLASSES_ROOT/Interface, and it may be a left over from previous attempts to use invoke ms-excel from withing VB.net which failed... pure guess.
is it possible to find out what this reference is? Can it be summarily deleted? Any hints on how to clear this warning will be appreciated.
Whatever the cause is, close VS, make a backup of the whole "Solution", then reopen, right-click and remove the reference under COM. If the project still compiles and runs then it was spurious.