Server error while editing

When editing an entry, the message “Server error. Due to a server error, we could not process this entry. The fields are temporarily locked so that you won’t lose any important changes.” appears and the field cannot be edited.
・Reloading the screen resumes editing.
・Browser extensions are not enabled.
・It occurs regardless of the time of day.
・“Failed to load resource: the server responded with a status of 500 ()” is displayed in the console of Google Chrome Developer Tools.

・Is there any impact on the total volume of entries?
・Is there any impact from the number of simultaneous editors in one space?