Thank you Aezaz for your guidance.
My theme is a paid theme and some of the layouts have been modified to suit my ads. Is it safe to switch to the default theme to check and reverse to my own theme. Will I be able to get back my initial customisation?
I had tried to install Classic Widget plugin as per your recommendation. I noticed that the problems come from my ad tags.
The error message shows:
This widget may have contained code that may work better in the “Custom HTML” widget. If you haven’t yet, how about trying that widget instead?
Below is one of the ad tags which has this error message:
<div id="ga_3429235"> </div><div style="text-align:right; width:300px; padding:5px 0;">
<img src="https://bcdn.grmtas.com/images/gourmetads-logo.jpg" alt="logo" style="float:right; border:none;" />
<div style="width:auto; padding:4px 5px 0 0; float:right; display:inline-block; font-family:Verdana, Geneva, sans-serif; font-size:11px; color:#333;">
<a href="https://www.gourmetads.com" target="_blank" title="Food Advertisements" style="text-decoration:none; color:#333;">Food Advertisements</a> by
</div>
</div>
Since the ad tag is fixed by my advertiser, what else should I try now? Thanks in advance.