Automation script no longer functions, issue isolated to the spreadsheet itself - google-apps-script

Question

I've been using Google Apps Script for about 2 months now to automate updating spreadsheets with information from a database. The scripts have been running this amount of time without any problems, until this week. Out of nowhere three of the scripts started failing. After diving into it I managed to fix two of the three spreadsheets, but one remains unresolved. One of the spreadsheets I fixed by manually clearing the sheet, despite that the script itself already does that. The other I had to create a new sheet for.
When running the script the log specifies that it is inserts the data as it should, but it clearly doesn't. It also displays an incorrect runtime (says between 15-20 seconds, but reality is 2-3 minutes). The exact error is
Execution failed: We're sorry, a server error occurred. Please wait a bit and try again.
The script itself triggers on a weekly basis. It duplicates the previous weeks sheet to maintain certain formatting and renames it, runs a query and inserts the resultset into the spreadsheet. Then it inserts a formula and that's it. The script still works. When using the script on a new spreadsheet it runs without a problem. It simply refuses to run on the existing spreadsheet, therefore I believe that that is where the problem lies.
I've tried manually clearing the old sheet (so before it gets duplicated), creating a new one, removing older sheets but all to no avail. The only solution I've encountered so far seems to be creating a new spreadsheet, but this isn't really an option. Some of these sheets are used by 40+ people on a daily basis. Having to replace and reshare a spreadsheet when this happens makes it a less reliable solution.
So my questions are why is this happening, and are there any solutions that will allow the use of the existing spreadsheet? Even if there is background data somewhere causing an error shouldn't that be removed when clearing a sheet.
Just in case I'll post the code snippit that writes to the spreadsheet, but I'm confident that this isn't the cause as it runs fine on a new spreadsheet and has run without a problem for nearly 2 months:
function buildWeek() {
var doc = SpreadsheetApp.getActiveSpreadsheet();
latestWeek();
var sheets = doc.getSheets();
var latestSheet = sheets[0];
Logger.log(latestSheet.getName());
var conn = Jdbc.getConnection("connection details");
var stmt = conn.createStatement();
var rs = stmt.executeQuery("query");
//Writing range start
var cell = latestSheet.getRange('A2');
var row = 0;
while (rs.next()) { // Inserts data from rows
var colcount = rs.getMetaData().getColumnCount();
for (var col = 0; col < colcount; col++) {
Logger.log(rs.getString(col + 1));
cell.offset(row, col).setValue(rs.getString(col + 1));
}
row++;
}