Can't open a coworker's models created in same version of LT that I use!!

[jhsdb]

Hi there, 

My new co-designer in our small company is working in Revit LT 2020 on her computer. I've got 2020 installed on my computer now (had 2019), and any old models of mine require an upgrade to 2020 before they'll open, but then they work fine. When I try to work on any models my coworker has worked on, even models I created initially, first they say I need to upgrade the model (which are Revit LT 2020  models already, so that's a red flag), and then I get this error and can't get any further. Any ideas? 

Thanks, Jenny in Chapel Hill NC

[syman2000]

Is your co-worker able to open the model you just opened? If yes, then try repairing your Revit LT 2020 or reinstall it.

[ennujozlagam]

try to tick audit the file before opening and see if helps. thanks