Hi, I had the version sketchup make, openstudio v2.1 and energy+ v8.4. Today I insalled the lastest version of energy plus v8.7, Now I can't open any idf file because there is an error of extension. I don't know what it means and why it happens. It's the first time I try those programmes.
In your EnergyPlus installation there is an application called "IDFVersionUpdater". You will need to run this on an .idf file to update it to the version of EnergyPlus you are using.
Try to open eplainch go to browse and select the file insteated to double clik on the file
Right-click the .idf file and select "Open with...". And then select EP-launch (from the installed location) and click "Always use this app to open .idf files". It worked for me, hope it works for you as well.
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