Hello Colander and welcome to the forum.
I am sorry to hear about the problems you are running into.
As this is primarily a user to user forum, someone-else may chip in. But please remember that the same symptoms do not necessarily mean the same problem.
Just to check: you are not using any Cloud storage for that folder are you? IF you are, try making it a local folder.
And, in passing, it's slightly odd that the install went into "Program Files (x86)" AS aT5 IS A 64-bit program and plug-in.
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Meanwhile, the best thing to do is
check the FAQs, via here. If they do not resolve the issue, there is a link at the top of the Search FAQs page to the Technical Support form, for some one to one investigation and help. Response time is usually within 2 working days (US (East Coast) Business hours, generally), but in the current circumstances please allow some more time.
And, to help others who run into a similar problem, please let us know what you did to resolve the problem. Please do not quote directly any correspondence from Support, as that may apply only to your particular circumstances and may lead others down the wrong track