Unable to open new or update existing files due to parse error

Need help fixing the parse error problem - I cannot open any files (new or old ones), I get to the “OPEN in IDE” but once I click that, I get the parse error and a broken file message (this one: The project ‘mySketch’ is damaged and cannot be opened due to a parse error. Examine the project file for invalid edits or unresolved source control conflicts.**) Since I have not used OF for 2 years, I have updated it, keeping the previous version. It worked *I have managed to open one file and then this started happening.

I would recommend you to run projectGenerator so the projects files are rebuilt for the specific OF version you are using.
Make a backup copy of the folder if you want.

If it doesn’t work you can paste screenshots of the error and specify platform, OF version and IDE you are using

Dear dimitre, thank you for your answer. I got it working by erasing the new version of OF and downloading it again.