Project Confusion

In some circumstances the following error message may be displayed when trying to open a project:

"Unable to open the project in <Project Path>."
"You should exit and restart PlantWise because the program is probably confused about the current project."

One possible reason is the User Equipment library has become corrupted:

<Project Path>\kbs\supers\user_equipment.kb

To check and possibly fix this, open user_equipment.kb with a text editor such as NotePad. Search the file for the word "Unknown" followed by a 0. If that appears, it means that the time stamp for a change to that class is incorrect.

It might be possible to fix the file as follows:

Save a backup copy of the file.
Search the line that contains :ALL-FRAMES for the class name that appears before the occurrence of "Unknown".
Remove the class name from that line.
Remove the line that contains ("Unknown" 0 "Unknown" 0)

For example, suppose this line is found in the file:

(:FRAME FAN ("Unknown" 0 "Unknown" 0) NIL NIL "" NIL NIL NIL NIL NIL NIL NIL)

This line should be deleted and the FAN class should be deleted from this line:

(:ALL-FRAMES ROOF REACTOR MOTOR_CONTROL FAN PUMP...)

which will be near the beginning of the file.

After making these edits, save the file and try opening the project again.