> The problem lies in your function mhistory_init_one() in Mudas.js:1965. You can only call "new MhistoryGraph(e)" with an element "e" which is something like
> 
> <div class="mjshistory" data-group="..." data-panel="..." data-base-u-r-l="https://host.psi.ch/?cmd=history" title="">
> 
> Please note the "data-base-u-r-l". This gets automatically added by the function mhistory_init() in mhistory.js:48. The URL is necessary sot that the upper right button in a history graph works which goes to a history page only showing the current graph.
> 
> In you function mhistory_init_one() you forgot the call
> 
>    mhist.dataset.baseURL = baseURL; 
> 
> where baseURL has to come from the current address bar like
> 
>    let baseURL = window.location.href;
>    if (baseURL.indexOf("?cmd") > 0)
>       baseURL = baseURL.substr(0, baseURL.indexOf("?cmd"));
>    baseURL += "?cmd=history";
> 
> If you duplicate some functionality from mhistory.js, please make sure to duplicate it completely.
> 

Thanks Stefan, but this was not the problem since I am setting the baseURL. You may have looked at the code during my debugging.

Some of my histories are placed in an IFrame object. I eventually realized that my code fails when it tries to resize a history which is placed in an invisible IFrame. I resolved the issue by making sure that I am resizing plots only if they are in a visible IFrame.