I keep getting an error message that this web page is reloaded because of an error

There was an issue with Safari 14.1 in an update the last week of April. Apple released a Safari 

"14.1" fix May 4/5.  Have you checked for the latest update?

I have details on the issue, a test to identify, work around and where to find the latest update here:

https://discussions.apple.com/thread/252710814?answerId=255146246022#255146246022

Read all postings, there is an update after the "Solution".

I hope this helps.

Install the latest update. Update may come with bug fixes.

Update Safari. https://support.apple.com/en-us/HT204416