You should be able to open a PLA created with any earlier version of AC prior to your current one up to a limit. If I took a guess that PLA was created with 17, an updated version of 16 (doubtful) or a an old AC07 (if this is the case you will need to look in the wiki for the steps to bring it forward).
The solution for 1 is having the architect save as AC16, the solution for 02 is for you to updated AC16 is a newer version is available which I think it is and for 03 is to look in the wiki.
Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
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